[PATCHv3 0/3] x86/mm/encrypt: Cleanup and switching between paging modes

[PATCHv3 0/3] x86/mm/encrypt: Cleanup and switching between paging modes

[Kirill A. Shutemov]

This patcheset is a preparation set for boot-time switching between
paging modes. Please review and consider applying.

Code around sme_populate_pgd() is unnecessary complex and hard to modify.

This patchset rewrites it in more stream-lined way to add support of
boot-time switching between paging modes.

I haven't tested the patchset on hardware capable of memory encryption.

v3:
 - Move all page table related functions into mem_encrypt_identity.c
v2:
 - Rebased to up-to-date tip

Kirill A. Shutemov (3):
  x86/mm/encrypt: Move page table helpers into separate translation unit
  x86/mm/encrypt: Rewrite sme_populate_pgd() and
    sme_populate_pgd_large()
  x86/mm/encrypt: Rewrite sme_pgtable_calc()

 arch/x86/mm/Makefile               |  14 +-
 arch/x86/mm/mem_encrypt.c          | 578 +------------------------------------
 arch/x86/mm/mem_encrypt_identity.c | 563 ++++++++++++++++++++++++++++++++++++
 arch/x86/mm/mm_internal.h          |   1 +
 4 files changed, 574 insertions(+), 582 deletions(-)
 create mode 100644 arch/x86/mm/mem_encrypt_identity.c

-- 
2.15.1

[PATCHv3 0/3] x86/mm/encrypt: Cleanup and switching between paging modes

[Kirill A. Shutemov]

This patcheset is a preparation set for boot-time switching between
paging modes. Please review and consider applying.

Code around sme_populate_pgd() is unnecessary complex and hard to modify.

This patchset rewrites it in more stream-lined way to add support of
boot-time switching between paging modes.

I haven't tested the patchset on hardware capable of memory encryption.

v3:
 - Move all page table related functions into mem_encrypt_identity.c
v2:
 - Rebased to up-to-date tip

Kirill A. Shutemov (3):
  x86/mm/encrypt: Move page table helpers into separate translation unit
  x86/mm/encrypt: Rewrite sme_populate_pgd() and
    sme_populate_pgd_large()
  x86/mm/encrypt: Rewrite sme_pgtable_calc()

 arch/x86/mm/Makefile               |  14 +-
 arch/x86/mm/mem_encrypt.c          | 578 +------------------------------------
 arch/x86/mm/mem_encrypt_identity.c | 563 ++++++++++++++++++++++++++++++++++++
 arch/x86/mm/mm_internal.h          |   1 +
 4 files changed, 574 insertions(+), 582 deletions(-)
 create mode 100644 arch/x86/mm/mem_encrypt_identity.c

-- 
2.15.1

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[PATCHv3 1/3] x86/mm/encrypt: Move page table helpers into separate translation unit

[Kirill A. Shutemov]

There are bunch of functions in mem_encrypt.c that operate on the
identity mapping, which means they want virtual addresses to be equal to
physical one, without PAGE_OFFSET shift.

We also need to avoid paravirtualizaion call there.

Getting this done is tricky. We cannot use usual page table helpers.
It forces us to open-code a lot of things. It makes code ugly and hard
to modify.

We can get it work with the page table helpers, but it requires few
preprocessor tricks. These tricks may have side effects for the rest of
the file.

Let's isolate such functions into own translation unit.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 arch/x86/mm/Makefile               |  14 +-
 arch/x86/mm/mem_encrypt.c          | 578 +----------------------------------
 arch/x86/mm/mem_encrypt_identity.c | 596 +++++++++++++++++++++++++++++++++++++
 arch/x86/mm/mm_internal.h          |   1 +
 4 files changed, 607 insertions(+), 582 deletions(-)
 create mode 100644 arch/x86/mm/mem_encrypt_identity.c

diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index 27e9e90a8d35..03c6c8561623 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -1,12 +1,15 @@
 # SPDX-License-Identifier: GPL-2.0
-# Kernel does not boot with instrumentation of tlb.c and mem_encrypt.c
-KCOV_INSTRUMENT_tlb.o		:= n
-KCOV_INSTRUMENT_mem_encrypt.o	:= n
+# Kernel does not boot with instrumentation of tlb.c and mem_encrypt*.c
+KCOV_INSTRUMENT_tlb.o			:= n
+KCOV_INSTRUMENT_mem_encrypt.o		:= n
+KCOV_INSTRUMENT_mem_encrypt_identity.o	:= n
 
-KASAN_SANITIZE_mem_encrypt.o	:= n
+KASAN_SANITIZE_mem_encrypt.o		:= n
+KASAN_SANITIZE_mem_encrypt_identity.o	:= n
 
 ifdef CONFIG_FUNCTION_TRACER
-CFLAGS_REMOVE_mem_encrypt.o	= -pg
+CFLAGS_REMOVE_mem_encrypt.o		= -pg
+CFLAGS_REMOVE_mem_encrypt_identity.o	= -pg
 endif
 
 obj-y	:=  init.o init_$(BITS).o fault.o ioremap.o extable.o pageattr.o mmap.o \
@@ -47,4 +50,5 @@ obj-$(CONFIG_RANDOMIZE_MEMORY)			+= kaslr.o
 obj-$(CONFIG_PAGE_TABLE_ISOLATION)		+= pti.o
 
 obj-$(CONFIG_AMD_MEM_ENCRYPT)	+= mem_encrypt.o
+obj-$(CONFIG_AMD_MEM_ENCRYPT)	+= mem_encrypt_identity.o
 obj-$(CONFIG_AMD_MEM_ENCRYPT)	+= mem_encrypt_boot.o
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index e1d61e8500f9..86f736b331ac 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -25,17 +25,12 @@
 #include <asm/bootparam.h>
 #include <asm/set_memory.h>
 #include <asm/cacheflush.h>
-#include <asm/sections.h>
 #include <asm/processor-flags.h>
 #include <asm/msr.h>
 #include <asm/cmdline.h>
 
 #include "mm_internal.h"
 
-static char sme_cmdline_arg[] __initdata = "mem_encrypt";
-static char sme_cmdline_on[]  __initdata = "on";
-static char sme_cmdline_off[] __initdata = "off";
-
 /*
  * Since SME related variables are set early in the boot process they must
  * reside in the .data section so as not to be zeroed out when the .bss
@@ -46,7 +41,7 @@ EXPORT_SYMBOL(sme_me_mask);
 DEFINE_STATIC_KEY_FALSE(sev_enable_key);
 EXPORT_SYMBOL_GPL(sev_enable_key);
 
-static bool sev_enabled __section(.data);
+bool sev_enabled __section(.data);
 
 /* Buffer used for early in-place encryption by BSP, no locking needed */
 static char sme_early_buffer[PAGE_SIZE] __aligned(PAGE_SIZE);
@@ -463,574 +458,3 @@ void swiotlb_set_mem_attributes(void *vaddr, unsigned long size)
 	/* Make the SWIOTLB buffer area decrypted */
 	set_memory_decrypted((unsigned long)vaddr, size >> PAGE_SHIFT);
 }
-
-struct sme_populate_pgd_data {
-	void	*pgtable_area;
-	pgd_t	*pgd;
-
-	pmdval_t pmd_flags;
-	pteval_t pte_flags;
-	unsigned long paddr;
-
-	unsigned long vaddr;
-	unsigned long vaddr_end;
-};
-
-static void __init sme_clear_pgd(struct sme_populate_pgd_data *ppd)
-{
-	unsigned long pgd_start, pgd_end, pgd_size;
-	pgd_t *pgd_p;
-
-	pgd_start = ppd->vaddr & PGDIR_MASK;
-	pgd_end = ppd->vaddr_end & PGDIR_MASK;
-
-	pgd_size = (((pgd_end - pgd_start) / PGDIR_SIZE) + 1) * sizeof(pgd_t);
-
-	pgd_p = ppd->pgd + pgd_index(ppd->vaddr);
-
-	memset(pgd_p, 0, pgd_size);
-}
-
-#define PGD_FLAGS		_KERNPG_TABLE_NOENC
-#define P4D_FLAGS		_KERNPG_TABLE_NOENC
-#define PUD_FLAGS		_KERNPG_TABLE_NOENC
-#define PMD_FLAGS		_KERNPG_TABLE_NOENC
-
-#define PMD_FLAGS_LARGE		(__PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL)
-
-#define PMD_FLAGS_DEC		PMD_FLAGS_LARGE
-#define PMD_FLAGS_DEC_WP	((PMD_FLAGS_DEC & ~_PAGE_CACHE_MASK) | \
-				 (_PAGE_PAT | _PAGE_PWT))
-
-#define PMD_FLAGS_ENC		(PMD_FLAGS_LARGE | _PAGE_ENC)
-
-#define PTE_FLAGS		(__PAGE_KERNEL_EXEC & ~_PAGE_GLOBAL)
-
-#define PTE_FLAGS_DEC		PTE_FLAGS
-#define PTE_FLAGS_DEC_WP	((PTE_FLAGS_DEC & ~_PAGE_CACHE_MASK) | \
-				 (_PAGE_PAT | _PAGE_PWT))
-
-#define PTE_FLAGS_ENC		(PTE_FLAGS | _PAGE_ENC)
-
-static pmd_t __init *sme_prepare_pgd(struct sme_populate_pgd_data *ppd)
-{
-	pgd_t *pgd_p;
-	p4d_t *p4d_p;
-	pud_t *pud_p;
-	pmd_t *pmd_p;
-
-	pgd_p = ppd->pgd + pgd_index(ppd->vaddr);
-	if (native_pgd_val(*pgd_p)) {
-		if (IS_ENABLED(CONFIG_X86_5LEVEL))
-			p4d_p = (p4d_t *)(native_pgd_val(*pgd_p) & ~PTE_FLAGS_MASK);
-		else
-			pud_p = (pud_t *)(native_pgd_val(*pgd_p) & ~PTE_FLAGS_MASK);
-	} else {
-		pgd_t pgd;
-
-		if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
-			p4d_p = ppd->pgtable_area;
-			memset(p4d_p, 0, sizeof(*p4d_p) * PTRS_PER_P4D);
-			ppd->pgtable_area += sizeof(*p4d_p) * PTRS_PER_P4D;
-
-			pgd = native_make_pgd((pgdval_t)p4d_p + PGD_FLAGS);
-		} else {
-			pud_p = ppd->pgtable_area;
-			memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
-			ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
-
-			pgd = native_make_pgd((pgdval_t)pud_p + PGD_FLAGS);
-		}
-		native_set_pgd(pgd_p, pgd);
-	}
-
-	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
-		p4d_p += p4d_index(ppd->vaddr);
-		if (native_p4d_val(*p4d_p)) {
-			pud_p = (pud_t *)(native_p4d_val(*p4d_p) & ~PTE_FLAGS_MASK);
-		} else {
-			p4d_t p4d;
-
-			pud_p = ppd->pgtable_area;
-			memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
-			ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
-
-			p4d = native_make_p4d((pudval_t)pud_p + P4D_FLAGS);
-			native_set_p4d(p4d_p, p4d);
-		}
-	}
-
-	pud_p += pud_index(ppd->vaddr);
-	if (native_pud_val(*pud_p)) {
-		if (native_pud_val(*pud_p) & _PAGE_PSE)
-			return NULL;
-
-		pmd_p = (pmd_t *)(native_pud_val(*pud_p) & ~PTE_FLAGS_MASK);
-	} else {
-		pud_t pud;
-
-		pmd_p = ppd->pgtable_area;
-		memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD);
-		ppd->pgtable_area += sizeof(*pmd_p) * PTRS_PER_PMD;
-
-		pud = native_make_pud((pmdval_t)pmd_p + PUD_FLAGS);
-		native_set_pud(pud_p, pud);
-	}
-
-	return pmd_p;
-}
-
-static void __init sme_populate_pgd_large(struct sme_populate_pgd_data *ppd)
-{
-	pmd_t *pmd_p;
-
-	pmd_p = sme_prepare_pgd(ppd);
-	if (!pmd_p)
-		return;
-
-	pmd_p += pmd_index(ppd->vaddr);
-	if (!native_pmd_val(*pmd_p) || !(native_pmd_val(*pmd_p) & _PAGE_PSE))
-		native_set_pmd(pmd_p, native_make_pmd(ppd->paddr | ppd->pmd_flags));
-}
-
-static void __init sme_populate_pgd(struct sme_populate_pgd_data *ppd)
-{
-	pmd_t *pmd_p;
-	pte_t *pte_p;
-
-	pmd_p = sme_prepare_pgd(ppd);
-	if (!pmd_p)
-		return;
-
-	pmd_p += pmd_index(ppd->vaddr);
-	if (native_pmd_val(*pmd_p)) {
-		if (native_pmd_val(*pmd_p) & _PAGE_PSE)
-			return;
-
-		pte_p = (pte_t *)(native_pmd_val(*pmd_p) & ~PTE_FLAGS_MASK);
-	} else {
-		pmd_t pmd;
-
-		pte_p = ppd->pgtable_area;
-		memset(pte_p, 0, sizeof(*pte_p) * PTRS_PER_PTE);
-		ppd->pgtable_area += sizeof(*pte_p) * PTRS_PER_PTE;
-
-		pmd = native_make_pmd((pteval_t)pte_p + PMD_FLAGS);
-		native_set_pmd(pmd_p, pmd);
-	}
-
-	pte_p += pte_index(ppd->vaddr);
-	if (!native_pte_val(*pte_p))
-		native_set_pte(pte_p, native_make_pte(ppd->paddr | ppd->pte_flags));
-}
-
-static void __init __sme_map_range_pmd(struct sme_populate_pgd_data *ppd)
-{
-	while (ppd->vaddr < ppd->vaddr_end) {
-		sme_populate_pgd_large(ppd);
-
-		ppd->vaddr += PMD_PAGE_SIZE;
-		ppd->paddr += PMD_PAGE_SIZE;
-	}
-}
-
-static void __init __sme_map_range_pte(struct sme_populate_pgd_data *ppd)
-{
-	while (ppd->vaddr < ppd->vaddr_end) {
-		sme_populate_pgd(ppd);
-
-		ppd->vaddr += PAGE_SIZE;
-		ppd->paddr += PAGE_SIZE;
-	}
-}
-
-static void __init __sme_map_range(struct sme_populate_pgd_data *ppd,
-				   pmdval_t pmd_flags, pteval_t pte_flags)
-{
-	unsigned long vaddr_end;
-
-	ppd->pmd_flags = pmd_flags;
-	ppd->pte_flags = pte_flags;
-
-	/* Save original end value since we modify the struct value */
-	vaddr_end = ppd->vaddr_end;
-
-	/* If start is not 2MB aligned, create PTE entries */
-	ppd->vaddr_end = ALIGN(ppd->vaddr, PMD_PAGE_SIZE);
-	__sme_map_range_pte(ppd);
-
-	/* Create PMD entries */
-	ppd->vaddr_end = vaddr_end & PMD_PAGE_MASK;
-	__sme_map_range_pmd(ppd);
-
-	/* If end is not 2MB aligned, create PTE entries */
-	ppd->vaddr_end = vaddr_end;
-	__sme_map_range_pte(ppd);
-}
-
-static void __init sme_map_range_encrypted(struct sme_populate_pgd_data *ppd)
-{
-	__sme_map_range(ppd, PMD_FLAGS_ENC, PTE_FLAGS_ENC);
-}
-
-static void __init sme_map_range_decrypted(struct sme_populate_pgd_data *ppd)
-{
-	__sme_map_range(ppd, PMD_FLAGS_DEC, PTE_FLAGS_DEC);
-}
-
-static void __init sme_map_range_decrypted_wp(struct sme_populate_pgd_data *ppd)
-{
-	__sme_map_range(ppd, PMD_FLAGS_DEC_WP, PTE_FLAGS_DEC_WP);
-}
-
-static unsigned long __init sme_pgtable_calc(unsigned long len)
-{
-	unsigned long p4d_size, pud_size, pmd_size, pte_size;
-	unsigned long total;
-
-	/*
-	 * Perform a relatively simplistic calculation of the pagetable
-	 * entries that are needed. Those mappings will be covered mostly
-	 * by 2MB PMD entries so we can conservatively calculate the required
-	 * number of P4D, PUD and PMD structures needed to perform the
-	 * mappings.  For mappings that are not 2MB aligned, PTE mappings
-	 * would be needed for the start and end portion of the address range
-	 * that fall outside of the 2MB alignment.  This results in, at most,
-	 * two extra pages to hold PTE entries for each range that is mapped.
-	 * Incrementing the count for each covers the case where the addresses
-	 * cross entries.
-	 */
-	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
-		p4d_size = (ALIGN(len, PGDIR_SIZE) / PGDIR_SIZE) + 1;
-		p4d_size *= sizeof(p4d_t) * PTRS_PER_P4D;
-		pud_size = (ALIGN(len, P4D_SIZE) / P4D_SIZE) + 1;
-		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
-	} else {
-		p4d_size = 0;
-		pud_size = (ALIGN(len, PGDIR_SIZE) / PGDIR_SIZE) + 1;
-		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
-	}
-	pmd_size = (ALIGN(len, PUD_SIZE) / PUD_SIZE) + 1;
-	pmd_size *= sizeof(pmd_t) * PTRS_PER_PMD;
-	pte_size = 2 * sizeof(pte_t) * PTRS_PER_PTE;
-
-	total = p4d_size + pud_size + pmd_size + pte_size;
-
-	/*
-	 * Now calculate the added pagetable structures needed to populate
-	 * the new pagetables.
-	 */
-	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
-		p4d_size = ALIGN(total, PGDIR_SIZE) / PGDIR_SIZE;
-		p4d_size *= sizeof(p4d_t) * PTRS_PER_P4D;
-		pud_size = ALIGN(total, P4D_SIZE) / P4D_SIZE;
-		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
-	} else {
-		p4d_size = 0;
-		pud_size = ALIGN(total, PGDIR_SIZE) / PGDIR_SIZE;
-		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
-	}
-	pmd_size = ALIGN(total, PUD_SIZE) / PUD_SIZE;
-	pmd_size *= sizeof(pmd_t) * PTRS_PER_PMD;
-
-	total += p4d_size + pud_size + pmd_size;
-
-	return total;
-}
-
-void __init __nostackprotector sme_encrypt_kernel(struct boot_params *bp)
-{
-	unsigned long workarea_start, workarea_end, workarea_len;
-	unsigned long execute_start, execute_end, execute_len;
-	unsigned long kernel_start, kernel_end, kernel_len;
-	unsigned long initrd_start, initrd_end, initrd_len;
-	struct sme_populate_pgd_data ppd;
-	unsigned long pgtable_area_len;
-	unsigned long decrypted_base;
-
-	if (!sme_active())
-		return;
-
-	/*
-	 * Prepare for encrypting the kernel and initrd by building new
-	 * pagetables with the necessary attributes needed to encrypt the
-	 * kernel in place.
-	 *
-	 *   One range of virtual addresses will map the memory occupied
-	 *   by the kernel and initrd as encrypted.
-	 *
-	 *   Another range of virtual addresses will map the memory occupied
-	 *   by the kernel and initrd as decrypted and write-protected.
-	 *
-	 *     The use of write-protect attribute will prevent any of the
-	 *     memory from being cached.
-	 */
-
-	/* Physical addresses gives us the identity mapped virtual addresses */
-	kernel_start = __pa_symbol(_text);
-	kernel_end = ALIGN(__pa_symbol(_end), PMD_PAGE_SIZE);
-	kernel_len = kernel_end - kernel_start;
-
-	initrd_start = 0;
-	initrd_end = 0;
-	initrd_len = 0;
-#ifdef CONFIG_BLK_DEV_INITRD
-	initrd_len = (unsigned long)bp->hdr.ramdisk_size |
-		     ((unsigned long)bp->ext_ramdisk_size << 32);
-	if (initrd_len) {
-		initrd_start = (unsigned long)bp->hdr.ramdisk_image |
-			       ((unsigned long)bp->ext_ramdisk_image << 32);
-		initrd_end = PAGE_ALIGN(initrd_start + initrd_len);
-		initrd_len = initrd_end - initrd_start;
-	}
-#endif
-
-	/* Set the encryption workarea to be immediately after the kernel */
-	workarea_start = kernel_end;
-
-	/*
-	 * Calculate required number of workarea bytes needed:
-	 *   executable encryption area size:
-	 *     stack page (PAGE_SIZE)
-	 *     encryption routine page (PAGE_SIZE)
-	 *     intermediate copy buffer (PMD_PAGE_SIZE)
-	 *   pagetable structures for the encryption of the kernel
-	 *   pagetable structures for workarea (in case not currently mapped)
-	 */
-	execute_start = workarea_start;
-	execute_end = execute_start + (PAGE_SIZE * 2) + PMD_PAGE_SIZE;
-	execute_len = execute_end - execute_start;
-
-	/*
-	 * One PGD for both encrypted and decrypted mappings and a set of
-	 * PUDs and PMDs for each of the encrypted and decrypted mappings.
-	 */
-	pgtable_area_len = sizeof(pgd_t) * PTRS_PER_PGD;
-	pgtable_area_len += sme_pgtable_calc(execute_end - kernel_start) * 2;
-	if (initrd_len)
-		pgtable_area_len += sme_pgtable_calc(initrd_len) * 2;
-
-	/* PUDs and PMDs needed in the current pagetables for the workarea */
-	pgtable_area_len += sme_pgtable_calc(execute_len + pgtable_area_len);
-
-	/*
-	 * The total workarea includes the executable encryption area and
-	 * the pagetable area. The start of the workarea is already 2MB
-	 * aligned, align the end of the workarea on a 2MB boundary so that
-	 * we don't try to create/allocate PTE entries from the workarea
-	 * before it is mapped.
-	 */
-	workarea_len = execute_len + pgtable_area_len;
-	workarea_end = ALIGN(workarea_start + workarea_len, PMD_PAGE_SIZE);
-
-	/*
-	 * Set the address to the start of where newly created pagetable
-	 * structures (PGDs, PUDs and PMDs) will be allocated. New pagetable
-	 * structures are created when the workarea is added to the current
-	 * pagetables and when the new encrypted and decrypted kernel
-	 * mappings are populated.
-	 */
-	ppd.pgtable_area = (void *)execute_end;
-
-	/*
-	 * Make sure the current pagetable structure has entries for
-	 * addressing the workarea.
-	 */
-	ppd.pgd = (pgd_t *)native_read_cr3_pa();
-	ppd.paddr = workarea_start;
-	ppd.vaddr = workarea_start;
-	ppd.vaddr_end = workarea_end;
-	sme_map_range_decrypted(&ppd);
-
-	/* Flush the TLB - no globals so cr3 is enough */
-	native_write_cr3(__native_read_cr3());
-
-	/*
-	 * A new pagetable structure is being built to allow for the kernel
-	 * and initrd to be encrypted. It starts with an empty PGD that will
-	 * then be populated with new PUDs and PMDs as the encrypted and
-	 * decrypted kernel mappings are created.
-	 */
-	ppd.pgd = ppd.pgtable_area;
-	memset(ppd.pgd, 0, sizeof(pgd_t) * PTRS_PER_PGD);
-	ppd.pgtable_area += sizeof(pgd_t) * PTRS_PER_PGD;
-
-	/*
-	 * A different PGD index/entry must be used to get different
-	 * pagetable entries for the decrypted mapping. Choose the next
-	 * PGD index and convert it to a virtual address to be used as
-	 * the base of the mapping.
-	 */
-	decrypted_base = (pgd_index(workarea_end) + 1) & (PTRS_PER_PGD - 1);
-	if (initrd_len) {
-		unsigned long check_base;
-
-		check_base = (pgd_index(initrd_end) + 1) & (PTRS_PER_PGD - 1);
-		decrypted_base = max(decrypted_base, check_base);
-	}
-	decrypted_base <<= PGDIR_SHIFT;
-
-	/* Add encrypted kernel (identity) mappings */
-	ppd.paddr = kernel_start;
-	ppd.vaddr = kernel_start;
-	ppd.vaddr_end = kernel_end;
-	sme_map_range_encrypted(&ppd);
-
-	/* Add decrypted, write-protected kernel (non-identity) mappings */
-	ppd.paddr = kernel_start;
-	ppd.vaddr = kernel_start + decrypted_base;
-	ppd.vaddr_end = kernel_end + decrypted_base;
-	sme_map_range_decrypted_wp(&ppd);
-
-	if (initrd_len) {
-		/* Add encrypted initrd (identity) mappings */
-		ppd.paddr = initrd_start;
-		ppd.vaddr = initrd_start;
-		ppd.vaddr_end = initrd_end;
-		sme_map_range_encrypted(&ppd);
-		/*
-		 * Add decrypted, write-protected initrd (non-identity) mappings
-		 */
-		ppd.paddr = initrd_start;
-		ppd.vaddr = initrd_start + decrypted_base;
-		ppd.vaddr_end = initrd_end + decrypted_base;
-		sme_map_range_decrypted_wp(&ppd);
-	}
-
-	/* Add decrypted workarea mappings to both kernel mappings */
-	ppd.paddr = workarea_start;
-	ppd.vaddr = workarea_start;
-	ppd.vaddr_end = workarea_end;
-	sme_map_range_decrypted(&ppd);
-
-	ppd.paddr = workarea_start;
-	ppd.vaddr = workarea_start + decrypted_base;
-	ppd.vaddr_end = workarea_end + decrypted_base;
-	sme_map_range_decrypted(&ppd);
-
-	/* Perform the encryption */
-	sme_encrypt_execute(kernel_start, kernel_start + decrypted_base,
-			    kernel_len, workarea_start, (unsigned long)ppd.pgd);
-
-	if (initrd_len)
-		sme_encrypt_execute(initrd_start, initrd_start + decrypted_base,
-				    initrd_len, workarea_start,
-				    (unsigned long)ppd.pgd);
-
-	/*
-	 * At this point we are running encrypted.  Remove the mappings for
-	 * the decrypted areas - all that is needed for this is to remove
-	 * the PGD entry/entries.
-	 */
-	ppd.vaddr = kernel_start + decrypted_base;
-	ppd.vaddr_end = kernel_end + decrypted_base;
-	sme_clear_pgd(&ppd);
-
-	if (initrd_len) {
-		ppd.vaddr = initrd_start + decrypted_base;
-		ppd.vaddr_end = initrd_end + decrypted_base;
-		sme_clear_pgd(&ppd);
-	}
-
-	ppd.vaddr = workarea_start + decrypted_base;
-	ppd.vaddr_end = workarea_end + decrypted_base;
-	sme_clear_pgd(&ppd);
-
-	/* Flush the TLB - no globals so cr3 is enough */
-	native_write_cr3(__native_read_cr3());
-}
-
-void __init __nostackprotector sme_enable(struct boot_params *bp)
-{
-	const char *cmdline_ptr, *cmdline_arg, *cmdline_on, *cmdline_off;
-	unsigned int eax, ebx, ecx, edx;
-	unsigned long feature_mask;
-	bool active_by_default;
-	unsigned long me_mask;
-	char buffer[16];
-	u64 msr;
-
-	/* Check for the SME/SEV support leaf */
-	eax = 0x80000000;
-	ecx = 0;
-	native_cpuid(&eax, &ebx, &ecx, &edx);
-	if (eax < 0x8000001f)
-		return;
-
-#define AMD_SME_BIT	BIT(0)
-#define AMD_SEV_BIT	BIT(1)
-	/*
-	 * Set the feature mask (SME or SEV) based on whether we are
-	 * running under a hypervisor.
-	 */
-	eax = 1;
-	ecx = 0;
-	native_cpuid(&eax, &ebx, &ecx, &edx);
-	feature_mask = (ecx & BIT(31)) ? AMD_SEV_BIT : AMD_SME_BIT;
-
-	/*
-	 * Check for the SME/SEV feature:
-	 *   CPUID Fn8000_001F[EAX]
-	 *   - Bit 0 - Secure Memory Encryption support
-	 *   - Bit 1 - Secure Encrypted Virtualization support
-	 *   CPUID Fn8000_001F[EBX]
-	 *   - Bits 5:0 - Pagetable bit position used to indicate encryption
-	 */
-	eax = 0x8000001f;
-	ecx = 0;
-	native_cpuid(&eax, &ebx, &ecx, &edx);
-	if (!(eax & feature_mask))
-		return;
-
-	me_mask = 1UL << (ebx & 0x3f);
-
-	/* Check if memory encryption is enabled */
-	if (feature_mask == AMD_SME_BIT) {
-		/* For SME, check the SYSCFG MSR */
-		msr = __rdmsr(MSR_K8_SYSCFG);
-		if (!(msr & MSR_K8_SYSCFG_MEM_ENCRYPT))
-			return;
-	} else {
-		/* For SEV, check the SEV MSR */
-		msr = __rdmsr(MSR_AMD64_SEV);
-		if (!(msr & MSR_AMD64_SEV_ENABLED))
-			return;
-
-		/* SEV state cannot be controlled by a command line option */
-		sme_me_mask = me_mask;
-		sev_enabled = true;
-		return;
-	}
-
-	/*
-	 * Fixups have not been applied to phys_base yet and we're running
-	 * identity mapped, so we must obtain the address to the SME command
-	 * line argument data using rip-relative addressing.
-	 */
-	asm ("lea sme_cmdline_arg(%%rip), %0"
-	     : "=r" (cmdline_arg)
-	     : "p" (sme_cmdline_arg));
-	asm ("lea sme_cmdline_on(%%rip), %0"
-	     : "=r" (cmdline_on)
-	     : "p" (sme_cmdline_on));
-	asm ("lea sme_cmdline_off(%%rip), %0"
-	     : "=r" (cmdline_off)
-	     : "p" (sme_cmdline_off));
-
-	if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT))
-		active_by_default = true;
-	else
-		active_by_default = false;
-
-	cmdline_ptr = (const char *)((u64)bp->hdr.cmd_line_ptr |
-				     ((u64)bp->ext_cmd_line_ptr << 32));
-
-	cmdline_find_option(cmdline_ptr, cmdline_arg, buffer, sizeof(buffer));
-
-	if (!strncmp(buffer, cmdline_on, sizeof(buffer)))
-		sme_me_mask = me_mask;
-	else if (!strncmp(buffer, cmdline_off, sizeof(buffer)))
-		sme_me_mask = 0;
-	else
-		sme_me_mask = active_by_default ? me_mask : 0;
-}
diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c
new file mode 100644
index 000000000000..c23d55cb25c4
--- /dev/null
+++ b/arch/x86/mm/mem_encrypt_identity.c
@@ -0,0 +1,596 @@
+/*
+ * AMD Memory Encryption Support
+ *
+ * Copyright (C) 2016 Advanced Micro Devices, Inc.
+ *
+ * Author: Tom Lendacky <thomas.lendacky@amd.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define DISABLE_BRANCH_PROFILING
+
+#include <linux/mm.h>
+
+#include <asm/setup.h>
+#include <asm/sections.h>
+#include <asm/cmdline.h>
+
+#include "mm_internal.h"
+
+#define PGD_FLAGS		_KERNPG_TABLE_NOENC
+#define P4D_FLAGS		_KERNPG_TABLE_NOENC
+#define PUD_FLAGS		_KERNPG_TABLE_NOENC
+#define PMD_FLAGS		_KERNPG_TABLE_NOENC
+
+#define PMD_FLAGS_LARGE		(__PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL)
+
+#define PMD_FLAGS_DEC		PMD_FLAGS_LARGE
+#define PMD_FLAGS_DEC_WP	((PMD_FLAGS_DEC & ~_PAGE_CACHE_MASK) | \
+				 (_PAGE_PAT | _PAGE_PWT))
+
+#define PMD_FLAGS_ENC		(PMD_FLAGS_LARGE | _PAGE_ENC)
+
+#define PTE_FLAGS		(__PAGE_KERNEL_EXEC & ~_PAGE_GLOBAL)
+
+#define PTE_FLAGS_DEC		PTE_FLAGS
+#define PTE_FLAGS_DEC_WP	((PTE_FLAGS_DEC & ~_PAGE_CACHE_MASK) | \
+				 (_PAGE_PAT | _PAGE_PWT))
+
+#define PTE_FLAGS_ENC		(PTE_FLAGS | _PAGE_ENC)
+
+struct sme_populate_pgd_data {
+	void    *pgtable_area;
+	pgd_t   *pgd;
+
+	pmdval_t pmd_flags;
+	pteval_t pte_flags;
+	unsigned long paddr;
+
+	unsigned long vaddr;
+	unsigned long vaddr_end;
+};
+
+static char sme_cmdline_arg[] __initdata = "mem_encrypt";
+static char sme_cmdline_on[]  __initdata = "on";
+static char sme_cmdline_off[] __initdata = "off";
+
+static void __init sme_clear_pgd(struct sme_populate_pgd_data *ppd)
+{
+	unsigned long pgd_start, pgd_end, pgd_size;
+	pgd_t *pgd_p;
+
+	pgd_start = ppd->vaddr & PGDIR_MASK;
+	pgd_end = ppd->vaddr_end & PGDIR_MASK;
+
+	pgd_size = (((pgd_end - pgd_start) / PGDIR_SIZE) + 1) * sizeof(pgd_t);
+
+	pgd_p = ppd->pgd + pgd_index(ppd->vaddr);
+
+	memset(pgd_p, 0, pgd_size);
+}
+
+static pmd_t __init *sme_prepare_pgd(struct sme_populate_pgd_data *ppd)
+{
+	pgd_t *pgd_p;
+	p4d_t *p4d_p;
+	pud_t *pud_p;
+	pmd_t *pmd_p;
+
+	pgd_p = ppd->pgd + pgd_index(ppd->vaddr);
+	if (native_pgd_val(*pgd_p)) {
+		if (IS_ENABLED(CONFIG_X86_5LEVEL))
+			p4d_p = (p4d_t *)(native_pgd_val(*pgd_p) & ~PTE_FLAGS_MASK);
+		else
+			pud_p = (pud_t *)(native_pgd_val(*pgd_p) & ~PTE_FLAGS_MASK);
+	} else {
+		pgd_t pgd;
+
+		if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+			p4d_p = ppd->pgtable_area;
+			memset(p4d_p, 0, sizeof(*p4d_p) * PTRS_PER_P4D);
+			ppd->pgtable_area += sizeof(*p4d_p) * PTRS_PER_P4D;
+
+			pgd = native_make_pgd((pgdval_t)p4d_p + PGD_FLAGS);
+		} else {
+			pud_p = ppd->pgtable_area;
+			memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
+			ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
+
+			pgd = native_make_pgd((pgdval_t)pud_p + PGD_FLAGS);
+		}
+		native_set_pgd(pgd_p, pgd);
+	}
+
+	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+		p4d_p += p4d_index(ppd->vaddr);
+		if (native_p4d_val(*p4d_p)) {
+			pud_p = (pud_t *)(native_p4d_val(*p4d_p) & ~PTE_FLAGS_MASK);
+		} else {
+			p4d_t p4d;
+
+			pud_p = ppd->pgtable_area;
+			memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
+			ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
+
+			p4d = native_make_p4d((pudval_t)pud_p + P4D_FLAGS);
+			native_set_p4d(p4d_p, p4d);
+		}
+	}
+
+	pud_p += pud_index(ppd->vaddr);
+	if (native_pud_val(*pud_p)) {
+		if (native_pud_val(*pud_p) & _PAGE_PSE)
+			return NULL;
+
+		pmd_p = (pmd_t *)(native_pud_val(*pud_p) & ~PTE_FLAGS_MASK);
+	} else {
+		pud_t pud;
+
+		pmd_p = ppd->pgtable_area;
+		memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD);
+		ppd->pgtable_area += sizeof(*pmd_p) * PTRS_PER_PMD;
+
+		pud = native_make_pud((pmdval_t)pmd_p + PUD_FLAGS);
+		native_set_pud(pud_p, pud);
+	}
+
+	return pmd_p;
+}
+
+static void __init sme_populate_pgd_large(struct sme_populate_pgd_data *ppd)
+{
+	pmd_t *pmd_p;
+
+	pmd_p = sme_prepare_pgd(ppd);
+	if (!pmd_p)
+		return;
+
+	pmd_p += pmd_index(ppd->vaddr);
+	if (!native_pmd_val(*pmd_p) || !(native_pmd_val(*pmd_p) & _PAGE_PSE))
+		native_set_pmd(pmd_p, native_make_pmd(ppd->paddr | ppd->pmd_flags));
+}
+
+static void __init sme_populate_pgd(struct sme_populate_pgd_data *ppd)
+{
+	pmd_t *pmd_p;
+	pte_t *pte_p;
+
+	pmd_p = sme_prepare_pgd(ppd);
+	if (!pmd_p)
+		return;
+
+	pmd_p += pmd_index(ppd->vaddr);
+	if (native_pmd_val(*pmd_p)) {
+		if (native_pmd_val(*pmd_p) & _PAGE_PSE)
+			return;
+
+		pte_p = (pte_t *)(native_pmd_val(*pmd_p) & ~PTE_FLAGS_MASK);
+	} else {
+		pmd_t pmd;
+
+		pte_p = ppd->pgtable_area;
+		memset(pte_p, 0, sizeof(*pte_p) * PTRS_PER_PTE);
+		ppd->pgtable_area += sizeof(*pte_p) * PTRS_PER_PTE;
+
+		pmd = native_make_pmd((pteval_t)pte_p + PMD_FLAGS);
+		native_set_pmd(pmd_p, pmd);
+	}
+
+	pte_p += pte_index(ppd->vaddr);
+	if (!native_pte_val(*pte_p))
+		native_set_pte(pte_p, native_make_pte(ppd->paddr | ppd->pte_flags));
+}
+
+static void __init __sme_map_range_pmd(struct sme_populate_pgd_data *ppd)
+{
+	while (ppd->vaddr < ppd->vaddr_end) {
+		sme_populate_pgd_large(ppd);
+
+		ppd->vaddr += PMD_PAGE_SIZE;
+		ppd->paddr += PMD_PAGE_SIZE;
+	}
+}
+
+static void __init __sme_map_range_pte(struct sme_populate_pgd_data *ppd)
+{
+	while (ppd->vaddr < ppd->vaddr_end) {
+		sme_populate_pgd(ppd);
+
+		ppd->vaddr += PAGE_SIZE;
+		ppd->paddr += PAGE_SIZE;
+	}
+}
+
+static void __init __sme_map_range(struct sme_populate_pgd_data *ppd,
+				   pmdval_t pmd_flags, pteval_t pte_flags)
+{
+	unsigned long vaddr_end;
+
+	ppd->pmd_flags = pmd_flags;
+	ppd->pte_flags = pte_flags;
+
+	/* Save original end value since we modify the struct value */
+	vaddr_end = ppd->vaddr_end;
+
+	/* If start is not 2MB aligned, create PTE entries */
+	ppd->vaddr_end = ALIGN(ppd->vaddr, PMD_PAGE_SIZE);
+	__sme_map_range_pte(ppd);
+
+	/* Create PMD entries */
+	ppd->vaddr_end = vaddr_end & PMD_PAGE_MASK;
+	__sme_map_range_pmd(ppd);
+
+	/* If end is not 2MB aligned, create PTE entries */
+	ppd->vaddr_end = vaddr_end;
+	__sme_map_range_pte(ppd);
+}
+
+static void __init sme_map_range_encrypted(struct sme_populate_pgd_data *ppd)
+{
+	__sme_map_range(ppd, PMD_FLAGS_ENC, PTE_FLAGS_ENC);
+}
+
+static void __init sme_map_range_decrypted(struct sme_populate_pgd_data *ppd)
+{
+	__sme_map_range(ppd, PMD_FLAGS_DEC, PTE_FLAGS_DEC);
+}
+
+static void __init sme_map_range_decrypted_wp(struct sme_populate_pgd_data *ppd)
+{
+	__sme_map_range(ppd, PMD_FLAGS_DEC_WP, PTE_FLAGS_DEC_WP);
+}
+
+static unsigned long __init sme_pgtable_calc(unsigned long len)
+{
+	unsigned long p4d_size, pud_size, pmd_size, pte_size;
+	unsigned long total;
+
+	/*
+	 * Perform a relatively simplistic calculation of the pagetable
+	 * entries that are needed. Those mappings will be covered mostly
+	 * by 2MB PMD entries so we can conservatively calculate the required
+	 * number of P4D, PUD and PMD structures needed to perform the
+	 * mappings.  For mappings that are not 2MB aligned, PTE mappings
+	 * would be needed for the start and end portion of the address range
+	 * that fall outside of the 2MB alignment.  This results in, at most,
+	 * two extra pages to hold PTE entries for each range that is mapped.
+	 * Incrementing the count for each covers the case where the addresses
+	 * cross entries.
+	 */
+	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+		p4d_size = (ALIGN(len, PGDIR_SIZE) / PGDIR_SIZE) + 1;
+		p4d_size *= sizeof(p4d_t) * PTRS_PER_P4D;
+		pud_size = (ALIGN(len, P4D_SIZE) / P4D_SIZE) + 1;
+		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
+	} else {
+		p4d_size = 0;
+		pud_size = (ALIGN(len, PGDIR_SIZE) / PGDIR_SIZE) + 1;
+		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
+	}
+	pmd_size = (ALIGN(len, PUD_SIZE) / PUD_SIZE) + 1;
+	pmd_size *= sizeof(pmd_t) * PTRS_PER_PMD;
+	pte_size = 2 * sizeof(pte_t) * PTRS_PER_PTE;
+
+	total = p4d_size + pud_size + pmd_size + pte_size;
+
+	/*
+	 * Now calculate the added pagetable structures needed to populate
+	 * the new pagetables.
+	 */
+	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+		p4d_size = ALIGN(total, PGDIR_SIZE) / PGDIR_SIZE;
+		p4d_size *= sizeof(p4d_t) * PTRS_PER_P4D;
+		pud_size = ALIGN(total, P4D_SIZE) / P4D_SIZE;
+		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
+	} else {
+		p4d_size = 0;
+		pud_size = ALIGN(total, PGDIR_SIZE) / PGDIR_SIZE;
+		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
+	}
+	pmd_size = ALIGN(total, PUD_SIZE) / PUD_SIZE;
+	pmd_size *= sizeof(pmd_t) * PTRS_PER_PMD;
+
+	total += p4d_size + pud_size + pmd_size;
+
+	return total;
+}
+
+void __init __nostackprotector sme_encrypt_kernel(struct boot_params *bp)
+{
+	unsigned long workarea_start, workarea_end, workarea_len;
+	unsigned long execute_start, execute_end, execute_len;
+	unsigned long kernel_start, kernel_end, kernel_len;
+	unsigned long initrd_start, initrd_end, initrd_len;
+	struct sme_populate_pgd_data ppd;
+	unsigned long pgtable_area_len;
+	unsigned long decrypted_base;
+
+	if (!sme_active())
+		return;
+
+	/*
+	 * Prepare for encrypting the kernel and initrd by building new
+	 * pagetables with the necessary attributes needed to encrypt the
+	 * kernel in place.
+	 *
+	 *   One range of virtual addresses will map the memory occupied
+	 *   by the kernel and initrd as encrypted.
+	 *
+	 *   Another range of virtual addresses will map the memory occupied
+	 *   by the kernel and initrd as decrypted and write-protected.
+	 *
+	 *     The use of write-protect attribute will prevent any of the
+	 *     memory from being cached.
+	 */
+
+	/* Physical addresses gives us the identity mapped virtual addresses */
+	kernel_start = __pa_symbol(_text);
+	kernel_end = ALIGN(__pa_symbol(_end), PMD_PAGE_SIZE);
+	kernel_len = kernel_end - kernel_start;
+
+	initrd_start = 0;
+	initrd_end = 0;
+	initrd_len = 0;
+#ifdef CONFIG_BLK_DEV_INITRD
+	initrd_len = (unsigned long)bp->hdr.ramdisk_size |
+		     ((unsigned long)bp->ext_ramdisk_size << 32);
+	if (initrd_len) {
+		initrd_start = (unsigned long)bp->hdr.ramdisk_image |
+			       ((unsigned long)bp->ext_ramdisk_image << 32);
+		initrd_end = PAGE_ALIGN(initrd_start + initrd_len);
+		initrd_len = initrd_end - initrd_start;
+	}
+#endif
+
+	/* Set the encryption workarea to be immediately after the kernel */
+	workarea_start = kernel_end;
+
+	/*
+	 * Calculate required number of workarea bytes needed:
+	 *   executable encryption area size:
+	 *     stack page (PAGE_SIZE)
+	 *     encryption routine page (PAGE_SIZE)
+	 *     intermediate copy buffer (PMD_PAGE_SIZE)
+	 *   pagetable structures for the encryption of the kernel
+	 *   pagetable structures for workarea (in case not currently mapped)
+	 */
+	execute_start = workarea_start;
+	execute_end = execute_start + (PAGE_SIZE * 2) + PMD_PAGE_SIZE;
+	execute_len = execute_end - execute_start;
+
+	/*
+	 * One PGD for both encrypted and decrypted mappings and a set of
+	 * PUDs and PMDs for each of the encrypted and decrypted mappings.
+	 */
+	pgtable_area_len = sizeof(pgd_t) * PTRS_PER_PGD;
+	pgtable_area_len += sme_pgtable_calc(execute_end - kernel_start) * 2;
+	if (initrd_len)
+		pgtable_area_len += sme_pgtable_calc(initrd_len) * 2;
+
+	/* PUDs and PMDs needed in the current pagetables for the workarea */
+	pgtable_area_len += sme_pgtable_calc(execute_len + pgtable_area_len);
+
+	/*
+	 * The total workarea includes the executable encryption area and
+	 * the pagetable area. The start of the workarea is already 2MB
+	 * aligned, align the end of the workarea on a 2MB boundary so that
+	 * we don't try to create/allocate PTE entries from the workarea
+	 * before it is mapped.
+	 */
+	workarea_len = execute_len + pgtable_area_len;
+	workarea_end = ALIGN(workarea_start + workarea_len, PMD_PAGE_SIZE);
+
+	/*
+	 * Set the address to the start of where newly created pagetable
+	 * structures (PGDs, PUDs and PMDs) will be allocated. New pagetable
+	 * structures are created when the workarea is added to the current
+	 * pagetables and when the new encrypted and decrypted kernel
+	 * mappings are populated.
+	 */
+	ppd.pgtable_area = (void *)execute_end;
+
+	/*
+	 * Make sure the current pagetable structure has entries for
+	 * addressing the workarea.
+	 */
+	ppd.pgd = (pgd_t *)native_read_cr3_pa();
+	ppd.paddr = workarea_start;
+	ppd.vaddr = workarea_start;
+	ppd.vaddr_end = workarea_end;
+	sme_map_range_decrypted(&ppd);
+
+	/* Flush the TLB - no globals so cr3 is enough */
+	native_write_cr3(__native_read_cr3());
+
+	/*
+	 * A new pagetable structure is being built to allow for the kernel
+	 * and initrd to be encrypted. It starts with an empty PGD that will
+	 * then be populated with new PUDs and PMDs as the encrypted and
+	 * decrypted kernel mappings are created.
+	 */
+	ppd.pgd = ppd.pgtable_area;
+	memset(ppd.pgd, 0, sizeof(pgd_t) * PTRS_PER_PGD);
+	ppd.pgtable_area += sizeof(pgd_t) * PTRS_PER_PGD;
+
+	/*
+	 * A different PGD index/entry must be used to get different
+	 * pagetable entries for the decrypted mapping. Choose the next
+	 * PGD index and convert it to a virtual address to be used as
+	 * the base of the mapping.
+	 */
+	decrypted_base = (pgd_index(workarea_end) + 1) & (PTRS_PER_PGD - 1);
+	if (initrd_len) {
+		unsigned long check_base;
+
+		check_base = (pgd_index(initrd_end) + 1) & (PTRS_PER_PGD - 1);
+		decrypted_base = max(decrypted_base, check_base);
+	}
+	decrypted_base <<= PGDIR_SHIFT;
+
+	/* Add encrypted kernel (identity) mappings */
+	ppd.paddr = kernel_start;
+	ppd.vaddr = kernel_start;
+	ppd.vaddr_end = kernel_end;
+	sme_map_range_encrypted(&ppd);
+
+	/* Add decrypted, write-protected kernel (non-identity) mappings */
+	ppd.paddr = kernel_start;
+	ppd.vaddr = kernel_start + decrypted_base;
+	ppd.vaddr_end = kernel_end + decrypted_base;
+	sme_map_range_decrypted_wp(&ppd);
+
+	if (initrd_len) {
+		/* Add encrypted initrd (identity) mappings */
+		ppd.paddr = initrd_start;
+		ppd.vaddr = initrd_start;
+		ppd.vaddr_end = initrd_end;
+		sme_map_range_encrypted(&ppd);
+		/*
+		 * Add decrypted, write-protected initrd (non-identity) mappings
+		 */
+		ppd.paddr = initrd_start;
+		ppd.vaddr = initrd_start + decrypted_base;
+		ppd.vaddr_end = initrd_end + decrypted_base;
+		sme_map_range_decrypted_wp(&ppd);
+	}
+
+	/* Add decrypted workarea mappings to both kernel mappings */
+	ppd.paddr = workarea_start;
+	ppd.vaddr = workarea_start;
+	ppd.vaddr_end = workarea_end;
+	sme_map_range_decrypted(&ppd);
+
+	ppd.paddr = workarea_start;
+	ppd.vaddr = workarea_start + decrypted_base;
+	ppd.vaddr_end = workarea_end + decrypted_base;
+	sme_map_range_decrypted(&ppd);
+
+	/* Perform the encryption */
+	sme_encrypt_execute(kernel_start, kernel_start + decrypted_base,
+			    kernel_len, workarea_start, (unsigned long)ppd.pgd);
+
+	if (initrd_len)
+		sme_encrypt_execute(initrd_start, initrd_start + decrypted_base,
+				    initrd_len, workarea_start,
+				    (unsigned long)ppd.pgd);
+
+	/*
+	 * At this point we are running encrypted.  Remove the mappings for
+	 * the decrypted areas - all that is needed for this is to remove
+	 * the PGD entry/entries.
+	 */
+	ppd.vaddr = kernel_start + decrypted_base;
+	ppd.vaddr_end = kernel_end + decrypted_base;
+	sme_clear_pgd(&ppd);
+
+	if (initrd_len) {
+		ppd.vaddr = initrd_start + decrypted_base;
+		ppd.vaddr_end = initrd_end + decrypted_base;
+		sme_clear_pgd(&ppd);
+	}
+
+	ppd.vaddr = workarea_start + decrypted_base;
+	ppd.vaddr_end = workarea_end + decrypted_base;
+	sme_clear_pgd(&ppd);
+
+	/* Flush the TLB - no globals so cr3 is enough */
+	native_write_cr3(__native_read_cr3());
+}
+
+void __init __nostackprotector sme_enable(struct boot_params *bp)
+{
+	const char *cmdline_ptr, *cmdline_arg, *cmdline_on, *cmdline_off;
+	unsigned int eax, ebx, ecx, edx;
+	unsigned long feature_mask;
+	bool active_by_default;
+	unsigned long me_mask;
+	char buffer[16];
+	u64 msr;
+
+	/* Check for the SME/SEV support leaf */
+	eax = 0x80000000;
+	ecx = 0;
+	native_cpuid(&eax, &ebx, &ecx, &edx);
+	if (eax < 0x8000001f)
+		return;
+
+#define AMD_SME_BIT	BIT(0)
+#define AMD_SEV_BIT	BIT(1)
+	/*
+	 * Set the feature mask (SME or SEV) based on whether we are
+	 * running under a hypervisor.
+	 */
+	eax = 1;
+	ecx = 0;
+	native_cpuid(&eax, &ebx, &ecx, &edx);
+	feature_mask = (ecx & BIT(31)) ? AMD_SEV_BIT : AMD_SME_BIT;
+
+	/*
+	 * Check for the SME/SEV feature:
+	 *   CPUID Fn8000_001F[EAX]
+	 *   - Bit 0 - Secure Memory Encryption support
+	 *   - Bit 1 - Secure Encrypted Virtualization support
+	 *   CPUID Fn8000_001F[EBX]
+	 *   - Bits 5:0 - Pagetable bit position used to indicate encryption
+	 */
+	eax = 0x8000001f;
+	ecx = 0;
+	native_cpuid(&eax, &ebx, &ecx, &edx);
+	if (!(eax & feature_mask))
+		return;
+
+	me_mask = 1UL << (ebx & 0x3f);
+
+	/* Check if memory encryption is enabled */
+	if (feature_mask == AMD_SME_BIT) {
+		/* For SME, check the SYSCFG MSR */
+		msr = __rdmsr(MSR_K8_SYSCFG);
+		if (!(msr & MSR_K8_SYSCFG_MEM_ENCRYPT))
+			return;
+	} else {
+		/* For SEV, check the SEV MSR */
+		msr = __rdmsr(MSR_AMD64_SEV);
+		if (!(msr & MSR_AMD64_SEV_ENABLED))
+			return;
+
+		/* SEV state cannot be controlled by a command line option */
+		sme_me_mask = me_mask;
+		sev_enabled = true;
+		return;
+	}
+
+	/*
+	 * Fixups have not been applied to phys_base yet and we're running
+	 * identity mapped, so we must obtain the address to the SME command
+	 * line argument data using rip-relative addressing.
+	 */
+	asm ("lea sme_cmdline_arg(%%rip), %0"
+	     : "=r" (cmdline_arg)
+	     : "p" (sme_cmdline_arg));
+	asm ("lea sme_cmdline_on(%%rip), %0"
+	     : "=r" (cmdline_on)
+	     : "p" (sme_cmdline_on));
+	asm ("lea sme_cmdline_off(%%rip), %0"
+	     : "=r" (cmdline_off)
+	     : "p" (sme_cmdline_off));
+
+	if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT))
+		active_by_default = true;
+	else
+		active_by_default = false;
+
+	cmdline_ptr = (const char *)((u64)bp->hdr.cmd_line_ptr |
+				     ((u64)bp->ext_cmd_line_ptr << 32));
+
+	cmdline_find_option(cmdline_ptr, cmdline_arg, buffer, sizeof(buffer));
+
+	if (!strncmp(buffer, cmdline_on, sizeof(buffer)))
+		sme_me_mask = me_mask;
+	else if (!strncmp(buffer, cmdline_off, sizeof(buffer)))
+		sme_me_mask = 0;
+	else
+		sme_me_mask = active_by_default ? me_mask : 0;
+}
diff --git a/arch/x86/mm/mm_internal.h b/arch/x86/mm/mm_internal.h
index 4e1f6e1b8159..7b4fc4386d90 100644
--- a/arch/x86/mm/mm_internal.h
+++ b/arch/x86/mm/mm_internal.h
@@ -19,4 +19,5 @@ extern int after_bootmem;
 
 void update_cache_mode_entry(unsigned entry, enum page_cache_mode cache);
 
+extern bool sev_enabled __section(.data);
 #endif	/* __X86_MM_INTERNAL_H */
-- 
2.15.1

[PATCHv3 1/3] x86/mm/encrypt: Move page table helpers into separate translation unit

[Kirill A. Shutemov]

There are bunch of functions in mem_encrypt.c that operate on the
identity mapping, which means they want virtual addresses to be equal to
physical one, without PAGE_OFFSET shift.

We also need to avoid paravirtualizaion call there.

Getting this done is tricky. We cannot use usual page table helpers.
It forces us to open-code a lot of things. It makes code ugly and hard
to modify.

We can get it work with the page table helpers, but it requires few
preprocessor tricks. These tricks may have side effects for the rest of
the file.

Let's isolate such functions into own translation unit.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 arch/x86/mm/Makefile               |  14 +-
 arch/x86/mm/mem_encrypt.c          | 578 +----------------------------------
 arch/x86/mm/mem_encrypt_identity.c | 596 +++++++++++++++++++++++++++++++++++++
 arch/x86/mm/mm_internal.h          |   1 +
 4 files changed, 607 insertions(+), 582 deletions(-)
 create mode 100644 arch/x86/mm/mem_encrypt_identity.c

diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index 27e9e90a8d35..03c6c8561623 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -1,12 +1,15 @@
 # SPDX-License-Identifier: GPL-2.0
-# Kernel does not boot with instrumentation of tlb.c and mem_encrypt.c
-KCOV_INSTRUMENT_tlb.o		:= n
-KCOV_INSTRUMENT_mem_encrypt.o	:= n
+# Kernel does not boot with instrumentation of tlb.c and mem_encrypt*.c
+KCOV_INSTRUMENT_tlb.o			:= n
+KCOV_INSTRUMENT_mem_encrypt.o		:= n
+KCOV_INSTRUMENT_mem_encrypt_identity.o	:= n
 
-KASAN_SANITIZE_mem_encrypt.o	:= n
+KASAN_SANITIZE_mem_encrypt.o		:= n
+KASAN_SANITIZE_mem_encrypt_identity.o	:= n
 
 ifdef CONFIG_FUNCTION_TRACER
-CFLAGS_REMOVE_mem_encrypt.o	= -pg
+CFLAGS_REMOVE_mem_encrypt.o		= -pg
+CFLAGS_REMOVE_mem_encrypt_identity.o	= -pg
 endif
 
 obj-y	:=  init.o init_$(BITS).o fault.o ioremap.o extable.o pageattr.o mmap.o \
@@ -47,4 +50,5 @@ obj-$(CONFIG_RANDOMIZE_MEMORY)			+= kaslr.o
 obj-$(CONFIG_PAGE_TABLE_ISOLATION)		+= pti.o
 
 obj-$(CONFIG_AMD_MEM_ENCRYPT)	+= mem_encrypt.o
+obj-$(CONFIG_AMD_MEM_ENCRYPT)	+= mem_encrypt_identity.o
 obj-$(CONFIG_AMD_MEM_ENCRYPT)	+= mem_encrypt_boot.o
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index e1d61e8500f9..86f736b331ac 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -25,17 +25,12 @@
 #include <asm/bootparam.h>
 #include <asm/set_memory.h>
 #include <asm/cacheflush.h>
-#include <asm/sections.h>
 #include <asm/processor-flags.h>
 #include <asm/msr.h>
 #include <asm/cmdline.h>
 
 #include "mm_internal.h"
 
-static char sme_cmdline_arg[] __initdata = "mem_encrypt";
-static char sme_cmdline_on[]  __initdata = "on";
-static char sme_cmdline_off[] __initdata = "off";
-
 /*
  * Since SME related variables are set early in the boot process they must
  * reside in the .data section so as not to be zeroed out when the .bss
@@ -46,7 +41,7 @@ EXPORT_SYMBOL(sme_me_mask);
 DEFINE_STATIC_KEY_FALSE(sev_enable_key);
 EXPORT_SYMBOL_GPL(sev_enable_key);
 
-static bool sev_enabled __section(.data);
+bool sev_enabled __section(.data);
 
 /* Buffer used for early in-place encryption by BSP, no locking needed */
 static char sme_early_buffer[PAGE_SIZE] __aligned(PAGE_SIZE);
@@ -463,574 +458,3 @@ void swiotlb_set_mem_attributes(void *vaddr, unsigned long size)
 	/* Make the SWIOTLB buffer area decrypted */
 	set_memory_decrypted((unsigned long)vaddr, size >> PAGE_SHIFT);
 }
-
-struct sme_populate_pgd_data {
-	void	*pgtable_area;
-	pgd_t	*pgd;
-
-	pmdval_t pmd_flags;
-	pteval_t pte_flags;
-	unsigned long paddr;
-
-	unsigned long vaddr;
-	unsigned long vaddr_end;
-};
-
-static void __init sme_clear_pgd(struct sme_populate_pgd_data *ppd)
-{
-	unsigned long pgd_start, pgd_end, pgd_size;
-	pgd_t *pgd_p;
-
-	pgd_start = ppd->vaddr & PGDIR_MASK;
-	pgd_end = ppd->vaddr_end & PGDIR_MASK;
-
-	pgd_size = (((pgd_end - pgd_start) / PGDIR_SIZE) + 1) * sizeof(pgd_t);
-
-	pgd_p = ppd->pgd + pgd_index(ppd->vaddr);
-
-	memset(pgd_p, 0, pgd_size);
-}
-
-#define PGD_FLAGS		_KERNPG_TABLE_NOENC
-#define P4D_FLAGS		_KERNPG_TABLE_NOENC
-#define PUD_FLAGS		_KERNPG_TABLE_NOENC
-#define PMD_FLAGS		_KERNPG_TABLE_NOENC
-
-#define PMD_FLAGS_LARGE		(__PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL)
-
-#define PMD_FLAGS_DEC		PMD_FLAGS_LARGE
-#define PMD_FLAGS_DEC_WP	((PMD_FLAGS_DEC & ~_PAGE_CACHE_MASK) | \
-				 (_PAGE_PAT | _PAGE_PWT))
-
-#define PMD_FLAGS_ENC		(PMD_FLAGS_LARGE | _PAGE_ENC)
-
-#define PTE_FLAGS		(__PAGE_KERNEL_EXEC & ~_PAGE_GLOBAL)
-
-#define PTE_FLAGS_DEC		PTE_FLAGS
-#define PTE_FLAGS_DEC_WP	((PTE_FLAGS_DEC & ~_PAGE_CACHE_MASK) | \
-				 (_PAGE_PAT | _PAGE_PWT))
-
-#define PTE_FLAGS_ENC		(PTE_FLAGS | _PAGE_ENC)
-
-static pmd_t __init *sme_prepare_pgd(struct sme_populate_pgd_data *ppd)
-{
-	pgd_t *pgd_p;
-	p4d_t *p4d_p;
-	pud_t *pud_p;
-	pmd_t *pmd_p;
-
-	pgd_p = ppd->pgd + pgd_index(ppd->vaddr);
-	if (native_pgd_val(*pgd_p)) {
-		if (IS_ENABLED(CONFIG_X86_5LEVEL))
-			p4d_p = (p4d_t *)(native_pgd_val(*pgd_p) & ~PTE_FLAGS_MASK);
-		else
-			pud_p = (pud_t *)(native_pgd_val(*pgd_p) & ~PTE_FLAGS_MASK);
-	} else {
-		pgd_t pgd;
-
-		if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
-			p4d_p = ppd->pgtable_area;
-			memset(p4d_p, 0, sizeof(*p4d_p) * PTRS_PER_P4D);
-			ppd->pgtable_area += sizeof(*p4d_p) * PTRS_PER_P4D;
-
-			pgd = native_make_pgd((pgdval_t)p4d_p + PGD_FLAGS);
-		} else {
-			pud_p = ppd->pgtable_area;
-			memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
-			ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
-
-			pgd = native_make_pgd((pgdval_t)pud_p + PGD_FLAGS);
-		}
-		native_set_pgd(pgd_p, pgd);
-	}
-
-	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
-		p4d_p += p4d_index(ppd->vaddr);
-		if (native_p4d_val(*p4d_p)) {
-			pud_p = (pud_t *)(native_p4d_val(*p4d_p) & ~PTE_FLAGS_MASK);
-		} else {
-			p4d_t p4d;
-
-			pud_p = ppd->pgtable_area;
-			memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
-			ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
-
-			p4d = native_make_p4d((pudval_t)pud_p + P4D_FLAGS);
-			native_set_p4d(p4d_p, p4d);
-		}
-	}
-
-	pud_p += pud_index(ppd->vaddr);
-	if (native_pud_val(*pud_p)) {
-		if (native_pud_val(*pud_p) & _PAGE_PSE)
-			return NULL;
-
-		pmd_p = (pmd_t *)(native_pud_val(*pud_p) & ~PTE_FLAGS_MASK);
-	} else {
-		pud_t pud;
-
-		pmd_p = ppd->pgtable_area;
-		memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD);
-		ppd->pgtable_area += sizeof(*pmd_p) * PTRS_PER_PMD;
-
-		pud = native_make_pud((pmdval_t)pmd_p + PUD_FLAGS);
-		native_set_pud(pud_p, pud);
-	}
-
-	return pmd_p;
-}
-
-static void __init sme_populate_pgd_large(struct sme_populate_pgd_data *ppd)
-{
-	pmd_t *pmd_p;
-
-	pmd_p = sme_prepare_pgd(ppd);
-	if (!pmd_p)
-		return;
-
-	pmd_p += pmd_index(ppd->vaddr);
-	if (!native_pmd_val(*pmd_p) || !(native_pmd_val(*pmd_p) & _PAGE_PSE))
-		native_set_pmd(pmd_p, native_make_pmd(ppd->paddr | ppd->pmd_flags));
-}
-
-static void __init sme_populate_pgd(struct sme_populate_pgd_data *ppd)
-{
-	pmd_t *pmd_p;
-	pte_t *pte_p;
-
-	pmd_p = sme_prepare_pgd(ppd);
-	if (!pmd_p)
-		return;
-
-	pmd_p += pmd_index(ppd->vaddr);
-	if (native_pmd_val(*pmd_p)) {
-		if (native_pmd_val(*pmd_p) & _PAGE_PSE)
-			return;
-
-		pte_p = (pte_t *)(native_pmd_val(*pmd_p) & ~PTE_FLAGS_MASK);
-	} else {
-		pmd_t pmd;
-
-		pte_p = ppd->pgtable_area;
-		memset(pte_p, 0, sizeof(*pte_p) * PTRS_PER_PTE);
-		ppd->pgtable_area += sizeof(*pte_p) * PTRS_PER_PTE;
-
-		pmd = native_make_pmd((pteval_t)pte_p + PMD_FLAGS);
-		native_set_pmd(pmd_p, pmd);
-	}
-
-	pte_p += pte_index(ppd->vaddr);
-	if (!native_pte_val(*pte_p))
-		native_set_pte(pte_p, native_make_pte(ppd->paddr | ppd->pte_flags));
-}
-
-static void __init __sme_map_range_pmd(struct sme_populate_pgd_data *ppd)
-{
-	while (ppd->vaddr < ppd->vaddr_end) {
-		sme_populate_pgd_large(ppd);
-
-		ppd->vaddr += PMD_PAGE_SIZE;
-		ppd->paddr += PMD_PAGE_SIZE;
-	}
-}
-
-static void __init __sme_map_range_pte(struct sme_populate_pgd_data *ppd)
-{
-	while (ppd->vaddr < ppd->vaddr_end) {
-		sme_populate_pgd(ppd);
-
-		ppd->vaddr += PAGE_SIZE;
-		ppd->paddr += PAGE_SIZE;
-	}
-}
-
-static void __init __sme_map_range(struct sme_populate_pgd_data *ppd,
-				   pmdval_t pmd_flags, pteval_t pte_flags)
-{
-	unsigned long vaddr_end;
-
-	ppd->pmd_flags = pmd_flags;
-	ppd->pte_flags = pte_flags;
-
-	/* Save original end value since we modify the struct value */
-	vaddr_end = ppd->vaddr_end;
-
-	/* If start is not 2MB aligned, create PTE entries */
-	ppd->vaddr_end = ALIGN(ppd->vaddr, PMD_PAGE_SIZE);
-	__sme_map_range_pte(ppd);
-
-	/* Create PMD entries */
-	ppd->vaddr_end = vaddr_end & PMD_PAGE_MASK;
-	__sme_map_range_pmd(ppd);
-
-	/* If end is not 2MB aligned, create PTE entries */
-	ppd->vaddr_end = vaddr_end;
-	__sme_map_range_pte(ppd);
-}
-
-static void __init sme_map_range_encrypted(struct sme_populate_pgd_data *ppd)
-{
-	__sme_map_range(ppd, PMD_FLAGS_ENC, PTE_FLAGS_ENC);
-}
-
-static void __init sme_map_range_decrypted(struct sme_populate_pgd_data *ppd)
-{
-	__sme_map_range(ppd, PMD_FLAGS_DEC, PTE_FLAGS_DEC);
-}
-
-static void __init sme_map_range_decrypted_wp(struct sme_populate_pgd_data *ppd)
-{
-	__sme_map_range(ppd, PMD_FLAGS_DEC_WP, PTE_FLAGS_DEC_WP);
-}
-
-static unsigned long __init sme_pgtable_calc(unsigned long len)
-{
-	unsigned long p4d_size, pud_size, pmd_size, pte_size;
-	unsigned long total;
-
-	/*
-	 * Perform a relatively simplistic calculation of the pagetable
-	 * entries that are needed. Those mappings will be covered mostly
-	 * by 2MB PMD entries so we can conservatively calculate the required
-	 * number of P4D, PUD and PMD structures needed to perform the
-	 * mappings.  For mappings that are not 2MB aligned, PTE mappings
-	 * would be needed for the start and end portion of the address range
-	 * that fall outside of the 2MB alignment.  This results in, at most,
-	 * two extra pages to hold PTE entries for each range that is mapped.
-	 * Incrementing the count for each covers the case where the addresses
-	 * cross entries.
-	 */
-	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
-		p4d_size = (ALIGN(len, PGDIR_SIZE) / PGDIR_SIZE) + 1;
-		p4d_size *= sizeof(p4d_t) * PTRS_PER_P4D;
-		pud_size = (ALIGN(len, P4D_SIZE) / P4D_SIZE) + 1;
-		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
-	} else {
-		p4d_size = 0;
-		pud_size = (ALIGN(len, PGDIR_SIZE) / PGDIR_SIZE) + 1;
-		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
-	}
-	pmd_size = (ALIGN(len, PUD_SIZE) / PUD_SIZE) + 1;
-	pmd_size *= sizeof(pmd_t) * PTRS_PER_PMD;
-	pte_size = 2 * sizeof(pte_t) * PTRS_PER_PTE;
-
-	total = p4d_size + pud_size + pmd_size + pte_size;
-
-	/*
-	 * Now calculate the added pagetable structures needed to populate
-	 * the new pagetables.
-	 */
-	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
-		p4d_size = ALIGN(total, PGDIR_SIZE) / PGDIR_SIZE;
-		p4d_size *= sizeof(p4d_t) * PTRS_PER_P4D;
-		pud_size = ALIGN(total, P4D_SIZE) / P4D_SIZE;
-		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
-	} else {
-		p4d_size = 0;
-		pud_size = ALIGN(total, PGDIR_SIZE) / PGDIR_SIZE;
-		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
-	}
-	pmd_size = ALIGN(total, PUD_SIZE) / PUD_SIZE;
-	pmd_size *= sizeof(pmd_t) * PTRS_PER_PMD;
-
-	total += p4d_size + pud_size + pmd_size;
-
-	return total;
-}
-
-void __init __nostackprotector sme_encrypt_kernel(struct boot_params *bp)
-{
-	unsigned long workarea_start, workarea_end, workarea_len;
-	unsigned long execute_start, execute_end, execute_len;
-	unsigned long kernel_start, kernel_end, kernel_len;
-	unsigned long initrd_start, initrd_end, initrd_len;
-	struct sme_populate_pgd_data ppd;
-	unsigned long pgtable_area_len;
-	unsigned long decrypted_base;
-
-	if (!sme_active())
-		return;
-
-	/*
-	 * Prepare for encrypting the kernel and initrd by building new
-	 * pagetables with the necessary attributes needed to encrypt the
-	 * kernel in place.
-	 *
-	 *   One range of virtual addresses will map the memory occupied
-	 *   by the kernel and initrd as encrypted.
-	 *
-	 *   Another range of virtual addresses will map the memory occupied
-	 *   by the kernel and initrd as decrypted and write-protected.
-	 *
-	 *     The use of write-protect attribute will prevent any of the
-	 *     memory from being cached.
-	 */
-
-	/* Physical addresses gives us the identity mapped virtual addresses */
-	kernel_start = __pa_symbol(_text);
-	kernel_end = ALIGN(__pa_symbol(_end), PMD_PAGE_SIZE);
-	kernel_len = kernel_end - kernel_start;
-
-	initrd_start = 0;
-	initrd_end = 0;
-	initrd_len = 0;
-#ifdef CONFIG_BLK_DEV_INITRD
-	initrd_len = (unsigned long)bp->hdr.ramdisk_size |
-		     ((unsigned long)bp->ext_ramdisk_size << 32);
-	if (initrd_len) {
-		initrd_start = (unsigned long)bp->hdr.ramdisk_image |
-			       ((unsigned long)bp->ext_ramdisk_image << 32);
-		initrd_end = PAGE_ALIGN(initrd_start + initrd_len);
-		initrd_len = initrd_end - initrd_start;
-	}
-#endif
-
-	/* Set the encryption workarea to be immediately after the kernel */
-	workarea_start = kernel_end;
-
-	/*
-	 * Calculate required number of workarea bytes needed:
-	 *   executable encryption area size:
-	 *     stack page (PAGE_SIZE)
-	 *     encryption routine page (PAGE_SIZE)
-	 *     intermediate copy buffer (PMD_PAGE_SIZE)
-	 *   pagetable structures for the encryption of the kernel
-	 *   pagetable structures for workarea (in case not currently mapped)
-	 */
-	execute_start = workarea_start;
-	execute_end = execute_start + (PAGE_SIZE * 2) + PMD_PAGE_SIZE;
-	execute_len = execute_end - execute_start;
-
-	/*
-	 * One PGD for both encrypted and decrypted mappings and a set of
-	 * PUDs and PMDs for each of the encrypted and decrypted mappings.
-	 */
-	pgtable_area_len = sizeof(pgd_t) * PTRS_PER_PGD;
-	pgtable_area_len += sme_pgtable_calc(execute_end - kernel_start) * 2;
-	if (initrd_len)
-		pgtable_area_len += sme_pgtable_calc(initrd_len) * 2;
-
-	/* PUDs and PMDs needed in the current pagetables for the workarea */
-	pgtable_area_len += sme_pgtable_calc(execute_len + pgtable_area_len);
-
-	/*
-	 * The total workarea includes the executable encryption area and
-	 * the pagetable area. The start of the workarea is already 2MB
-	 * aligned, align the end of the workarea on a 2MB boundary so that
-	 * we don't try to create/allocate PTE entries from the workarea
-	 * before it is mapped.
-	 */
-	workarea_len = execute_len + pgtable_area_len;
-	workarea_end = ALIGN(workarea_start + workarea_len, PMD_PAGE_SIZE);
-
-	/*
-	 * Set the address to the start of where newly created pagetable
-	 * structures (PGDs, PUDs and PMDs) will be allocated. New pagetable
-	 * structures are created when the workarea is added to the current
-	 * pagetables and when the new encrypted and decrypted kernel
-	 * mappings are populated.
-	 */
-	ppd.pgtable_area = (void *)execute_end;
-
-	/*
-	 * Make sure the current pagetable structure has entries for
-	 * addressing the workarea.
-	 */
-	ppd.pgd = (pgd_t *)native_read_cr3_pa();
-	ppd.paddr = workarea_start;
-	ppd.vaddr = workarea_start;
-	ppd.vaddr_end = workarea_end;
-	sme_map_range_decrypted(&ppd);
-
-	/* Flush the TLB - no globals so cr3 is enough */
-	native_write_cr3(__native_read_cr3());
-
-	/*
-	 * A new pagetable structure is being built to allow for the kernel
-	 * and initrd to be encrypted. It starts with an empty PGD that will
-	 * then be populated with new PUDs and PMDs as the encrypted and
-	 * decrypted kernel mappings are created.
-	 */
-	ppd.pgd = ppd.pgtable_area;
-	memset(ppd.pgd, 0, sizeof(pgd_t) * PTRS_PER_PGD);
-	ppd.pgtable_area += sizeof(pgd_t) * PTRS_PER_PGD;
-
-	/*
-	 * A different PGD index/entry must be used to get different
-	 * pagetable entries for the decrypted mapping. Choose the next
-	 * PGD index and convert it to a virtual address to be used as
-	 * the base of the mapping.
-	 */
-	decrypted_base = (pgd_index(workarea_end) + 1) & (PTRS_PER_PGD - 1);
-	if (initrd_len) {
-		unsigned long check_base;
-
-		check_base = (pgd_index(initrd_end) + 1) & (PTRS_PER_PGD - 1);
-		decrypted_base = max(decrypted_base, check_base);
-	}
-	decrypted_base <<= PGDIR_SHIFT;
-
-	/* Add encrypted kernel (identity) mappings */
-	ppd.paddr = kernel_start;
-	ppd.vaddr = kernel_start;
-	ppd.vaddr_end = kernel_end;
-	sme_map_range_encrypted(&ppd);
-
-	/* Add decrypted, write-protected kernel (non-identity) mappings */
-	ppd.paddr = kernel_start;
-	ppd.vaddr = kernel_start + decrypted_base;
-	ppd.vaddr_end = kernel_end + decrypted_base;
-	sme_map_range_decrypted_wp(&ppd);
-
-	if (initrd_len) {
-		/* Add encrypted initrd (identity) mappings */
-		ppd.paddr = initrd_start;
-		ppd.vaddr = initrd_start;
-		ppd.vaddr_end = initrd_end;
-		sme_map_range_encrypted(&ppd);
-		/*
-		 * Add decrypted, write-protected initrd (non-identity) mappings
-		 */
-		ppd.paddr = initrd_start;
-		ppd.vaddr = initrd_start + decrypted_base;
-		ppd.vaddr_end = initrd_end + decrypted_base;
-		sme_map_range_decrypted_wp(&ppd);
-	}
-
-	/* Add decrypted workarea mappings to both kernel mappings */
-	ppd.paddr = workarea_start;
-	ppd.vaddr = workarea_start;
-	ppd.vaddr_end = workarea_end;
-	sme_map_range_decrypted(&ppd);
-
-	ppd.paddr = workarea_start;
-	ppd.vaddr = workarea_start + decrypted_base;
-	ppd.vaddr_end = workarea_end + decrypted_base;
-	sme_map_range_decrypted(&ppd);
-
-	/* Perform the encryption */
-	sme_encrypt_execute(kernel_start, kernel_start + decrypted_base,
-			    kernel_len, workarea_start, (unsigned long)ppd.pgd);
-
-	if (initrd_len)
-		sme_encrypt_execute(initrd_start, initrd_start + decrypted_base,
-				    initrd_len, workarea_start,
-				    (unsigned long)ppd.pgd);
-
-	/*
-	 * At this point we are running encrypted.  Remove the mappings for
-	 * the decrypted areas - all that is needed for this is to remove
-	 * the PGD entry/entries.
-	 */
-	ppd.vaddr = kernel_start + decrypted_base;
-	ppd.vaddr_end = kernel_end + decrypted_base;
-	sme_clear_pgd(&ppd);
-
-	if (initrd_len) {
-		ppd.vaddr = initrd_start + decrypted_base;
-		ppd.vaddr_end = initrd_end + decrypted_base;
-		sme_clear_pgd(&ppd);
-	}
-
-	ppd.vaddr = workarea_start + decrypted_base;
-	ppd.vaddr_end = workarea_end + decrypted_base;
-	sme_clear_pgd(&ppd);
-
-	/* Flush the TLB - no globals so cr3 is enough */
-	native_write_cr3(__native_read_cr3());
-}
-
-void __init __nostackprotector sme_enable(struct boot_params *bp)
-{
-	const char *cmdline_ptr, *cmdline_arg, *cmdline_on, *cmdline_off;
-	unsigned int eax, ebx, ecx, edx;
-	unsigned long feature_mask;
-	bool active_by_default;
-	unsigned long me_mask;
-	char buffer[16];
-	u64 msr;
-
-	/* Check for the SME/SEV support leaf */
-	eax = 0x80000000;
-	ecx = 0;
-	native_cpuid(&eax, &ebx, &ecx, &edx);
-	if (eax < 0x8000001f)
-		return;
-
-#define AMD_SME_BIT	BIT(0)
-#define AMD_SEV_BIT	BIT(1)
-	/*
-	 * Set the feature mask (SME or SEV) based on whether we are
-	 * running under a hypervisor.
-	 */
-	eax = 1;
-	ecx = 0;
-	native_cpuid(&eax, &ebx, &ecx, &edx);
-	feature_mask = (ecx & BIT(31)) ? AMD_SEV_BIT : AMD_SME_BIT;
-
-	/*
-	 * Check for the SME/SEV feature:
-	 *   CPUID Fn8000_001F[EAX]
-	 *   - Bit 0 - Secure Memory Encryption support
-	 *   - Bit 1 - Secure Encrypted Virtualization support
-	 *   CPUID Fn8000_001F[EBX]
-	 *   - Bits 5:0 - Pagetable bit position used to indicate encryption
-	 */
-	eax = 0x8000001f;
-	ecx = 0;
-	native_cpuid(&eax, &ebx, &ecx, &edx);
-	if (!(eax & feature_mask))
-		return;
-
-	me_mask = 1UL << (ebx & 0x3f);
-
-	/* Check if memory encryption is enabled */
-	if (feature_mask == AMD_SME_BIT) {
-		/* For SME, check the SYSCFG MSR */
-		msr = __rdmsr(MSR_K8_SYSCFG);
-		if (!(msr & MSR_K8_SYSCFG_MEM_ENCRYPT))
-			return;
-	} else {
-		/* For SEV, check the SEV MSR */
-		msr = __rdmsr(MSR_AMD64_SEV);
-		if (!(msr & MSR_AMD64_SEV_ENABLED))
-			return;
-
-		/* SEV state cannot be controlled by a command line option */
-		sme_me_mask = me_mask;
-		sev_enabled = true;
-		return;
-	}
-
-	/*
-	 * Fixups have not been applied to phys_base yet and we're running
-	 * identity mapped, so we must obtain the address to the SME command
-	 * line argument data using rip-relative addressing.
-	 */
-	asm ("lea sme_cmdline_arg(%%rip), %0"
-	     : "=r" (cmdline_arg)
-	     : "p" (sme_cmdline_arg));
-	asm ("lea sme_cmdline_on(%%rip), %0"
-	     : "=r" (cmdline_on)
-	     : "p" (sme_cmdline_on));
-	asm ("lea sme_cmdline_off(%%rip), %0"
-	     : "=r" (cmdline_off)
-	     : "p" (sme_cmdline_off));
-
-	if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT))
-		active_by_default = true;
-	else
-		active_by_default = false;
-
-	cmdline_ptr = (const char *)((u64)bp->hdr.cmd_line_ptr |
-				     ((u64)bp->ext_cmd_line_ptr << 32));
-
-	cmdline_find_option(cmdline_ptr, cmdline_arg, buffer, sizeof(buffer));
-
-	if (!strncmp(buffer, cmdline_on, sizeof(buffer)))
-		sme_me_mask = me_mask;
-	else if (!strncmp(buffer, cmdline_off, sizeof(buffer)))
-		sme_me_mask = 0;
-	else
-		sme_me_mask = active_by_default ? me_mask : 0;
-}
diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c
new file mode 100644
index 000000000000..c23d55cb25c4
--- /dev/null
+++ b/arch/x86/mm/mem_encrypt_identity.c
@@ -0,0 +1,596 @@
+/*
+ * AMD Memory Encryption Support
+ *
+ * Copyright (C) 2016 Advanced Micro Devices, Inc.
+ *
+ * Author: Tom Lendacky <thomas.lendacky@amd.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define DISABLE_BRANCH_PROFILING
+
+#include <linux/mm.h>
+
+#include <asm/setup.h>
+#include <asm/sections.h>
+#include <asm/cmdline.h>
+
+#include "mm_internal.h"
+
+#define PGD_FLAGS		_KERNPG_TABLE_NOENC
+#define P4D_FLAGS		_KERNPG_TABLE_NOENC
+#define PUD_FLAGS		_KERNPG_TABLE_NOENC
+#define PMD_FLAGS		_KERNPG_TABLE_NOENC
+
+#define PMD_FLAGS_LARGE		(__PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL)
+
+#define PMD_FLAGS_DEC		PMD_FLAGS_LARGE
+#define PMD_FLAGS_DEC_WP	((PMD_FLAGS_DEC & ~_PAGE_CACHE_MASK) | \
+				 (_PAGE_PAT | _PAGE_PWT))
+
+#define PMD_FLAGS_ENC		(PMD_FLAGS_LARGE | _PAGE_ENC)
+
+#define PTE_FLAGS		(__PAGE_KERNEL_EXEC & ~_PAGE_GLOBAL)
+
+#define PTE_FLAGS_DEC		PTE_FLAGS
+#define PTE_FLAGS_DEC_WP	((PTE_FLAGS_DEC & ~_PAGE_CACHE_MASK) | \
+				 (_PAGE_PAT | _PAGE_PWT))
+
+#define PTE_FLAGS_ENC		(PTE_FLAGS | _PAGE_ENC)
+
+struct sme_populate_pgd_data {
+	void    *pgtable_area;
+	pgd_t   *pgd;
+
+	pmdval_t pmd_flags;
+	pteval_t pte_flags;
+	unsigned long paddr;
+
+	unsigned long vaddr;
+	unsigned long vaddr_end;
+};
+
+static char sme_cmdline_arg[] __initdata = "mem_encrypt";
+static char sme_cmdline_on[]  __initdata = "on";
+static char sme_cmdline_off[] __initdata = "off";
+
+static void __init sme_clear_pgd(struct sme_populate_pgd_data *ppd)
+{
+	unsigned long pgd_start, pgd_end, pgd_size;
+	pgd_t *pgd_p;
+
+	pgd_start = ppd->vaddr & PGDIR_MASK;
+	pgd_end = ppd->vaddr_end & PGDIR_MASK;
+
+	pgd_size = (((pgd_end - pgd_start) / PGDIR_SIZE) + 1) * sizeof(pgd_t);
+
+	pgd_p = ppd->pgd + pgd_index(ppd->vaddr);
+
+	memset(pgd_p, 0, pgd_size);
+}
+
+static pmd_t __init *sme_prepare_pgd(struct sme_populate_pgd_data *ppd)
+{
+	pgd_t *pgd_p;
+	p4d_t *p4d_p;
+	pud_t *pud_p;
+	pmd_t *pmd_p;
+
+	pgd_p = ppd->pgd + pgd_index(ppd->vaddr);
+	if (native_pgd_val(*pgd_p)) {
+		if (IS_ENABLED(CONFIG_X86_5LEVEL))
+			p4d_p = (p4d_t *)(native_pgd_val(*pgd_p) & ~PTE_FLAGS_MASK);
+		else
+			pud_p = (pud_t *)(native_pgd_val(*pgd_p) & ~PTE_FLAGS_MASK);
+	} else {
+		pgd_t pgd;
+
+		if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+			p4d_p = ppd->pgtable_area;
+			memset(p4d_p, 0, sizeof(*p4d_p) * PTRS_PER_P4D);
+			ppd->pgtable_area += sizeof(*p4d_p) * PTRS_PER_P4D;
+
+			pgd = native_make_pgd((pgdval_t)p4d_p + PGD_FLAGS);
+		} else {
+			pud_p = ppd->pgtable_area;
+			memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
+			ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
+
+			pgd = native_make_pgd((pgdval_t)pud_p + PGD_FLAGS);
+		}
+		native_set_pgd(pgd_p, pgd);
+	}
+
+	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+		p4d_p += p4d_index(ppd->vaddr);
+		if (native_p4d_val(*p4d_p)) {
+			pud_p = (pud_t *)(native_p4d_val(*p4d_p) & ~PTE_FLAGS_MASK);
+		} else {
+			p4d_t p4d;
+
+			pud_p = ppd->pgtable_area;
+			memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
+			ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
+
+			p4d = native_make_p4d((pudval_t)pud_p + P4D_FLAGS);
+			native_set_p4d(p4d_p, p4d);
+		}
+	}
+
+	pud_p += pud_index(ppd->vaddr);
+	if (native_pud_val(*pud_p)) {
+		if (native_pud_val(*pud_p) & _PAGE_PSE)
+			return NULL;
+
+		pmd_p = (pmd_t *)(native_pud_val(*pud_p) & ~PTE_FLAGS_MASK);
+	} else {
+		pud_t pud;
+
+		pmd_p = ppd->pgtable_area;
+		memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD);
+		ppd->pgtable_area += sizeof(*pmd_p) * PTRS_PER_PMD;
+
+		pud = native_make_pud((pmdval_t)pmd_p + PUD_FLAGS);
+		native_set_pud(pud_p, pud);
+	}
+
+	return pmd_p;
+}
+
+static void __init sme_populate_pgd_large(struct sme_populate_pgd_data *ppd)
+{
+	pmd_t *pmd_p;
+
+	pmd_p = sme_prepare_pgd(ppd);
+	if (!pmd_p)
+		return;
+
+	pmd_p += pmd_index(ppd->vaddr);
+	if (!native_pmd_val(*pmd_p) || !(native_pmd_val(*pmd_p) & _PAGE_PSE))
+		native_set_pmd(pmd_p, native_make_pmd(ppd->paddr | ppd->pmd_flags));
+}
+
+static void __init sme_populate_pgd(struct sme_populate_pgd_data *ppd)
+{
+	pmd_t *pmd_p;
+	pte_t *pte_p;
+
+	pmd_p = sme_prepare_pgd(ppd);
+	if (!pmd_p)
+		return;
+
+	pmd_p += pmd_index(ppd->vaddr);
+	if (native_pmd_val(*pmd_p)) {
+		if (native_pmd_val(*pmd_p) & _PAGE_PSE)
+			return;
+
+		pte_p = (pte_t *)(native_pmd_val(*pmd_p) & ~PTE_FLAGS_MASK);
+	} else {
+		pmd_t pmd;
+
+		pte_p = ppd->pgtable_area;
+		memset(pte_p, 0, sizeof(*pte_p) * PTRS_PER_PTE);
+		ppd->pgtable_area += sizeof(*pte_p) * PTRS_PER_PTE;
+
+		pmd = native_make_pmd((pteval_t)pte_p + PMD_FLAGS);
+		native_set_pmd(pmd_p, pmd);
+	}
+
+	pte_p += pte_index(ppd->vaddr);
+	if (!native_pte_val(*pte_p))
+		native_set_pte(pte_p, native_make_pte(ppd->paddr | ppd->pte_flags));
+}
+
+static void __init __sme_map_range_pmd(struct sme_populate_pgd_data *ppd)
+{
+	while (ppd->vaddr < ppd->vaddr_end) {
+		sme_populate_pgd_large(ppd);
+
+		ppd->vaddr += PMD_PAGE_SIZE;
+		ppd->paddr += PMD_PAGE_SIZE;
+	}
+}
+
+static void __init __sme_map_range_pte(struct sme_populate_pgd_data *ppd)
+{
+	while (ppd->vaddr < ppd->vaddr_end) {
+		sme_populate_pgd(ppd);
+
+		ppd->vaddr += PAGE_SIZE;
+		ppd->paddr += PAGE_SIZE;
+	}
+}
+
+static void __init __sme_map_range(struct sme_populate_pgd_data *ppd,
+				   pmdval_t pmd_flags, pteval_t pte_flags)
+{
+	unsigned long vaddr_end;
+
+	ppd->pmd_flags = pmd_flags;
+	ppd->pte_flags = pte_flags;
+
+	/* Save original end value since we modify the struct value */
+	vaddr_end = ppd->vaddr_end;
+
+	/* If start is not 2MB aligned, create PTE entries */
+	ppd->vaddr_end = ALIGN(ppd->vaddr, PMD_PAGE_SIZE);
+	__sme_map_range_pte(ppd);
+
+	/* Create PMD entries */
+	ppd->vaddr_end = vaddr_end & PMD_PAGE_MASK;
+	__sme_map_range_pmd(ppd);
+
+	/* If end is not 2MB aligned, create PTE entries */
+	ppd->vaddr_end = vaddr_end;
+	__sme_map_range_pte(ppd);
+}
+
+static void __init sme_map_range_encrypted(struct sme_populate_pgd_data *ppd)
+{
+	__sme_map_range(ppd, PMD_FLAGS_ENC, PTE_FLAGS_ENC);
+}
+
+static void __init sme_map_range_decrypted(struct sme_populate_pgd_data *ppd)
+{
+	__sme_map_range(ppd, PMD_FLAGS_DEC, PTE_FLAGS_DEC);
+}
+
+static void __init sme_map_range_decrypted_wp(struct sme_populate_pgd_data *ppd)
+{
+	__sme_map_range(ppd, PMD_FLAGS_DEC_WP, PTE_FLAGS_DEC_WP);
+}
+
+static unsigned long __init sme_pgtable_calc(unsigned long len)
+{
+	unsigned long p4d_size, pud_size, pmd_size, pte_size;
+	unsigned long total;
+
+	/*
+	 * Perform a relatively simplistic calculation of the pagetable
+	 * entries that are needed. Those mappings will be covered mostly
+	 * by 2MB PMD entries so we can conservatively calculate the required
+	 * number of P4D, PUD and PMD structures needed to perform the
+	 * mappings.  For mappings that are not 2MB aligned, PTE mappings
+	 * would be needed for the start and end portion of the address range
+	 * that fall outside of the 2MB alignment.  This results in, at most,
+	 * two extra pages to hold PTE entries for each range that is mapped.
+	 * Incrementing the count for each covers the case where the addresses
+	 * cross entries.
+	 */
+	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+		p4d_size = (ALIGN(len, PGDIR_SIZE) / PGDIR_SIZE) + 1;
+		p4d_size *= sizeof(p4d_t) * PTRS_PER_P4D;
+		pud_size = (ALIGN(len, P4D_SIZE) / P4D_SIZE) + 1;
+		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
+	} else {
+		p4d_size = 0;
+		pud_size = (ALIGN(len, PGDIR_SIZE) / PGDIR_SIZE) + 1;
+		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
+	}
+	pmd_size = (ALIGN(len, PUD_SIZE) / PUD_SIZE) + 1;
+	pmd_size *= sizeof(pmd_t) * PTRS_PER_PMD;
+	pte_size = 2 * sizeof(pte_t) * PTRS_PER_PTE;
+
+	total = p4d_size + pud_size + pmd_size + pte_size;
+
+	/*
+	 * Now calculate the added pagetable structures needed to populate
+	 * the new pagetables.
+	 */
+	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+		p4d_size = ALIGN(total, PGDIR_SIZE) / PGDIR_SIZE;
+		p4d_size *= sizeof(p4d_t) * PTRS_PER_P4D;
+		pud_size = ALIGN(total, P4D_SIZE) / P4D_SIZE;
+		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
+	} else {
+		p4d_size = 0;
+		pud_size = ALIGN(total, PGDIR_SIZE) / PGDIR_SIZE;
+		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
+	}
+	pmd_size = ALIGN(total, PUD_SIZE) / PUD_SIZE;
+	pmd_size *= sizeof(pmd_t) * PTRS_PER_PMD;
+
+	total += p4d_size + pud_size + pmd_size;
+
+	return total;
+}
+
+void __init __nostackprotector sme_encrypt_kernel(struct boot_params *bp)
+{
+	unsigned long workarea_start, workarea_end, workarea_len;
+	unsigned long execute_start, execute_end, execute_len;
+	unsigned long kernel_start, kernel_end, kernel_len;
+	unsigned long initrd_start, initrd_end, initrd_len;
+	struct sme_populate_pgd_data ppd;
+	unsigned long pgtable_area_len;
+	unsigned long decrypted_base;
+
+	if (!sme_active())
+		return;
+
+	/*
+	 * Prepare for encrypting the kernel and initrd by building new
+	 * pagetables with the necessary attributes needed to encrypt the
+	 * kernel in place.
+	 *
+	 *   One range of virtual addresses will map the memory occupied
+	 *   by the kernel and initrd as encrypted.
+	 *
+	 *   Another range of virtual addresses will map the memory occupied
+	 *   by the kernel and initrd as decrypted and write-protected.
+	 *
+	 *     The use of write-protect attribute will prevent any of the
+	 *     memory from being cached.
+	 */
+
+	/* Physical addresses gives us the identity mapped virtual addresses */
+	kernel_start = __pa_symbol(_text);
+	kernel_end = ALIGN(__pa_symbol(_end), PMD_PAGE_SIZE);
+	kernel_len = kernel_end - kernel_start;
+
+	initrd_start = 0;
+	initrd_end = 0;
+	initrd_len = 0;
+#ifdef CONFIG_BLK_DEV_INITRD
+	initrd_len = (unsigned long)bp->hdr.ramdisk_size |
+		     ((unsigned long)bp->ext_ramdisk_size << 32);
+	if (initrd_len) {
+		initrd_start = (unsigned long)bp->hdr.ramdisk_image |
+			       ((unsigned long)bp->ext_ramdisk_image << 32);
+		initrd_end = PAGE_ALIGN(initrd_start + initrd_len);
+		initrd_len = initrd_end - initrd_start;
+	}
+#endif
+
+	/* Set the encryption workarea to be immediately after the kernel */
+	workarea_start = kernel_end;
+
+	/*
+	 * Calculate required number of workarea bytes needed:
+	 *   executable encryption area size:
+	 *     stack page (PAGE_SIZE)
+	 *     encryption routine page (PAGE_SIZE)
+	 *     intermediate copy buffer (PMD_PAGE_SIZE)
+	 *   pagetable structures for the encryption of the kernel
+	 *   pagetable structures for workarea (in case not currently mapped)
+	 */
+	execute_start = workarea_start;
+	execute_end = execute_start + (PAGE_SIZE * 2) + PMD_PAGE_SIZE;
+	execute_len = execute_end - execute_start;
+
+	/*
+	 * One PGD for both encrypted and decrypted mappings and a set of
+	 * PUDs and PMDs for each of the encrypted and decrypted mappings.
+	 */
+	pgtable_area_len = sizeof(pgd_t) * PTRS_PER_PGD;
+	pgtable_area_len += sme_pgtable_calc(execute_end - kernel_start) * 2;
+	if (initrd_len)
+		pgtable_area_len += sme_pgtable_calc(initrd_len) * 2;
+
+	/* PUDs and PMDs needed in the current pagetables for the workarea */
+	pgtable_area_len += sme_pgtable_calc(execute_len + pgtable_area_len);
+
+	/*
+	 * The total workarea includes the executable encryption area and
+	 * the pagetable area. The start of the workarea is already 2MB
+	 * aligned, align the end of the workarea on a 2MB boundary so that
+	 * we don't try to create/allocate PTE entries from the workarea
+	 * before it is mapped.
+	 */
+	workarea_len = execute_len + pgtable_area_len;
+	workarea_end = ALIGN(workarea_start + workarea_len, PMD_PAGE_SIZE);
+
+	/*
+	 * Set the address to the start of where newly created pagetable
+	 * structures (PGDs, PUDs and PMDs) will be allocated. New pagetable
+	 * structures are created when the workarea is added to the current
+	 * pagetables and when the new encrypted and decrypted kernel
+	 * mappings are populated.
+	 */
+	ppd.pgtable_area = (void *)execute_end;
+
+	/*
+	 * Make sure the current pagetable structure has entries for
+	 * addressing the workarea.
+	 */
+	ppd.pgd = (pgd_t *)native_read_cr3_pa();
+	ppd.paddr = workarea_start;
+	ppd.vaddr = workarea_start;
+	ppd.vaddr_end = workarea_end;
+	sme_map_range_decrypted(&ppd);
+
+	/* Flush the TLB - no globals so cr3 is enough */
+	native_write_cr3(__native_read_cr3());
+
+	/*
+	 * A new pagetable structure is being built to allow for the kernel
+	 * and initrd to be encrypted. It starts with an empty PGD that will
+	 * then be populated with new PUDs and PMDs as the encrypted and
+	 * decrypted kernel mappings are created.
+	 */
+	ppd.pgd = ppd.pgtable_area;
+	memset(ppd.pgd, 0, sizeof(pgd_t) * PTRS_PER_PGD);
+	ppd.pgtable_area += sizeof(pgd_t) * PTRS_PER_PGD;
+
+	/*
+	 * A different PGD index/entry must be used to get different
+	 * pagetable entries for the decrypted mapping. Choose the next
+	 * PGD index and convert it to a virtual address to be used as
+	 * the base of the mapping.
+	 */
+	decrypted_base = (pgd_index(workarea_end) + 1) & (PTRS_PER_PGD - 1);
+	if (initrd_len) {
+		unsigned long check_base;
+
+		check_base = (pgd_index(initrd_end) + 1) & (PTRS_PER_PGD - 1);
+		decrypted_base = max(decrypted_base, check_base);
+	}
+	decrypted_base <<= PGDIR_SHIFT;
+
+	/* Add encrypted kernel (identity) mappings */
+	ppd.paddr = kernel_start;
+	ppd.vaddr = kernel_start;
+	ppd.vaddr_end = kernel_end;
+	sme_map_range_encrypted(&ppd);
+
+	/* Add decrypted, write-protected kernel (non-identity) mappings */
+	ppd.paddr = kernel_start;
+	ppd.vaddr = kernel_start + decrypted_base;
+	ppd.vaddr_end = kernel_end + decrypted_base;
+	sme_map_range_decrypted_wp(&ppd);
+
+	if (initrd_len) {
+		/* Add encrypted initrd (identity) mappings */
+		ppd.paddr = initrd_start;
+		ppd.vaddr = initrd_start;
+		ppd.vaddr_end = initrd_end;
+		sme_map_range_encrypted(&ppd);
+		/*
+		 * Add decrypted, write-protected initrd (non-identity) mappings
+		 */
+		ppd.paddr = initrd_start;
+		ppd.vaddr = initrd_start + decrypted_base;
+		ppd.vaddr_end = initrd_end + decrypted_base;
+		sme_map_range_decrypted_wp(&ppd);
+	}
+
+	/* Add decrypted workarea mappings to both kernel mappings */
+	ppd.paddr = workarea_start;
+	ppd.vaddr = workarea_start;
+	ppd.vaddr_end = workarea_end;
+	sme_map_range_decrypted(&ppd);
+
+	ppd.paddr = workarea_start;
+	ppd.vaddr = workarea_start + decrypted_base;
+	ppd.vaddr_end = workarea_end + decrypted_base;
+	sme_map_range_decrypted(&ppd);
+
+	/* Perform the encryption */
+	sme_encrypt_execute(kernel_start, kernel_start + decrypted_base,
+			    kernel_len, workarea_start, (unsigned long)ppd.pgd);
+
+	if (initrd_len)
+		sme_encrypt_execute(initrd_start, initrd_start + decrypted_base,
+				    initrd_len, workarea_start,
+				    (unsigned long)ppd.pgd);
+
+	/*
+	 * At this point we are running encrypted.  Remove the mappings for
+	 * the decrypted areas - all that is needed for this is to remove
+	 * the PGD entry/entries.
+	 */
+	ppd.vaddr = kernel_start + decrypted_base;
+	ppd.vaddr_end = kernel_end + decrypted_base;
+	sme_clear_pgd(&ppd);
+
+	if (initrd_len) {
+		ppd.vaddr = initrd_start + decrypted_base;
+		ppd.vaddr_end = initrd_end + decrypted_base;
+		sme_clear_pgd(&ppd);
+	}
+
+	ppd.vaddr = workarea_start + decrypted_base;
+	ppd.vaddr_end = workarea_end + decrypted_base;
+	sme_clear_pgd(&ppd);
+
+	/* Flush the TLB - no globals so cr3 is enough */
+	native_write_cr3(__native_read_cr3());
+}
+
+void __init __nostackprotector sme_enable(struct boot_params *bp)
+{
+	const char *cmdline_ptr, *cmdline_arg, *cmdline_on, *cmdline_off;
+	unsigned int eax, ebx, ecx, edx;
+	unsigned long feature_mask;
+	bool active_by_default;
+	unsigned long me_mask;
+	char buffer[16];
+	u64 msr;
+
+	/* Check for the SME/SEV support leaf */
+	eax = 0x80000000;
+	ecx = 0;
+	native_cpuid(&eax, &ebx, &ecx, &edx);
+	if (eax < 0x8000001f)
+		return;
+
+#define AMD_SME_BIT	BIT(0)
+#define AMD_SEV_BIT	BIT(1)
+	/*
+	 * Set the feature mask (SME or SEV) based on whether we are
+	 * running under a hypervisor.
+	 */
+	eax = 1;
+	ecx = 0;
+	native_cpuid(&eax, &ebx, &ecx, &edx);
+	feature_mask = (ecx & BIT(31)) ? AMD_SEV_BIT : AMD_SME_BIT;
+
+	/*
+	 * Check for the SME/SEV feature:
+	 *   CPUID Fn8000_001F[EAX]
+	 *   - Bit 0 - Secure Memory Encryption support
+	 *   - Bit 1 - Secure Encrypted Virtualization support
+	 *   CPUID Fn8000_001F[EBX]
+	 *   - Bits 5:0 - Pagetable bit position used to indicate encryption
+	 */
+	eax = 0x8000001f;
+	ecx = 0;
+	native_cpuid(&eax, &ebx, &ecx, &edx);
+	if (!(eax & feature_mask))
+		return;
+
+	me_mask = 1UL << (ebx & 0x3f);
+
+	/* Check if memory encryption is enabled */
+	if (feature_mask == AMD_SME_BIT) {
+		/* For SME, check the SYSCFG MSR */
+		msr = __rdmsr(MSR_K8_SYSCFG);
+		if (!(msr & MSR_K8_SYSCFG_MEM_ENCRYPT))
+			return;
+	} else {
+		/* For SEV, check the SEV MSR */
+		msr = __rdmsr(MSR_AMD64_SEV);
+		if (!(msr & MSR_AMD64_SEV_ENABLED))
+			return;
+
+		/* SEV state cannot be controlled by a command line option */
+		sme_me_mask = me_mask;
+		sev_enabled = true;
+		return;
+	}
+
+	/*
+	 * Fixups have not been applied to phys_base yet and we're running
+	 * identity mapped, so we must obtain the address to the SME command
+	 * line argument data using rip-relative addressing.
+	 */
+	asm ("lea sme_cmdline_arg(%%rip), %0"
+	     : "=r" (cmdline_arg)
+	     : "p" (sme_cmdline_arg));
+	asm ("lea sme_cmdline_on(%%rip), %0"
+	     : "=r" (cmdline_on)
+	     : "p" (sme_cmdline_on));
+	asm ("lea sme_cmdline_off(%%rip), %0"
+	     : "=r" (cmdline_off)
+	     : "p" (sme_cmdline_off));
+
+	if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT))
+		active_by_default = true;
+	else
+		active_by_default = false;
+
+	cmdline_ptr = (const char *)((u64)bp->hdr.cmd_line_ptr |
+				     ((u64)bp->ext_cmd_line_ptr << 32));
+
+	cmdline_find_option(cmdline_ptr, cmdline_arg, buffer, sizeof(buffer));
+
+	if (!strncmp(buffer, cmdline_on, sizeof(buffer)))
+		sme_me_mask = me_mask;
+	else if (!strncmp(buffer, cmdline_off, sizeof(buffer)))
+		sme_me_mask = 0;
+	else
+		sme_me_mask = active_by_default ? me_mask : 0;
+}
diff --git a/arch/x86/mm/mm_internal.h b/arch/x86/mm/mm_internal.h
index 4e1f6e1b8159..7b4fc4386d90 100644
--- a/arch/x86/mm/mm_internal.h
+++ b/arch/x86/mm/mm_internal.h
@@ -19,4 +19,5 @@ extern int after_bootmem;
 
 void update_cache_mode_entry(unsigned entry, enum page_cache_mode cache);
 
+extern bool sev_enabled __section(.data);
 #endif	/* __X86_MM_INTERNAL_H */
-- 
2.15.1

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Re: [PATCHv3 1/3] x86/mm/encrypt: Move page table helpers into separate translation unit

[Tom Lendacky]

On 1/24/2018 10:36 AM, Kirill A. Shutemov wrote:
> There are bunch of functions in mem_encrypt.c that operate on the
> identity mapping, which means they want virtual addresses to be equal to
> physical one, without PAGE_OFFSET shift.
> 
> We also need to avoid paravirtualizaion call there.
> 
> Getting this done is tricky. We cannot use usual page table helpers.
> It forces us to open-code a lot of things. It makes code ugly and hard
> to modify.
> 
> We can get it work with the page table helpers, but it requires few
> preprocessor tricks. These tricks may have side effects for the rest of
> the file.
> 
> Let's isolate such functions into own translation unit.
> 
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>

Just one minor comment at the end.  With that change:

Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>

> ---
>  arch/x86/mm/Makefile               |  14 +-
>  arch/x86/mm/mem_encrypt.c          | 578 +----------------------------------
>  arch/x86/mm/mem_encrypt_identity.c | 596 +++++++++++++++++++++++++++++++++++++
>  arch/x86/mm/mm_internal.h          |   1 +
>  4 files changed, 607 insertions(+), 582 deletions(-)
>  create mode 100644 arch/x86/mm/mem_encrypt_identity.c
> 

...

> diff --git a/arch/x86/mm/mm_internal.h b/arch/x86/mm/mm_internal.h
> index 4e1f6e1b8159..7b4fc4386d90 100644
> --- a/arch/x86/mm/mm_internal.h
> +++ b/arch/x86/mm/mm_internal.h
> @@ -19,4 +19,5 @@ extern int after_bootmem;
>  
>  void update_cache_mode_entry(unsigned entry, enum page_cache_mode cache);
>  
> +extern bool sev_enabled __section(.data);

Lets move this into arch/x86/include/asm/mem_encrypt.h and then add
#include <linux/mem_encrypt.h> to mem_encrypt_identity.c.

Thanks,
Tom

>  #endif	/* __X86_MM_INTERNAL_H */
> 

Re: [PATCHv3 1/3] x86/mm/encrypt: Move page table helpers into separate translation unit

[Tom Lendacky]

On 1/24/2018 10:36 AM, Kirill A. Shutemov wrote:
> There are bunch of functions in mem_encrypt.c that operate on the
> identity mapping, which means they want virtual addresses to be equal to
> physical one, without PAGE_OFFSET shift.
> 
> We also need to avoid paravirtualizaion call there.
> 
> Getting this done is tricky. We cannot use usual page table helpers.
> It forces us to open-code a lot of things. It makes code ugly and hard
> to modify.
> 
> We can get it work with the page table helpers, but it requires few
> preprocessor tricks. These tricks may have side effects for the rest of
> the file.
> 
> Let's isolate such functions into own translation unit.
> 
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>

Just one minor comment at the end.  With that change:

Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>

> ---
>  arch/x86/mm/Makefile               |  14 +-
>  arch/x86/mm/mem_encrypt.c          | 578 +----------------------------------
>  arch/x86/mm/mem_encrypt_identity.c | 596 +++++++++++++++++++++++++++++++++++++
>  arch/x86/mm/mm_internal.h          |   1 +
>  4 files changed, 607 insertions(+), 582 deletions(-)
>  create mode 100644 arch/x86/mm/mem_encrypt_identity.c
> 

...

> diff --git a/arch/x86/mm/mm_internal.h b/arch/x86/mm/mm_internal.h
> index 4e1f6e1b8159..7b4fc4386d90 100644
> --- a/arch/x86/mm/mm_internal.h
> +++ b/arch/x86/mm/mm_internal.h
> @@ -19,4 +19,5 @@ extern int after_bootmem;
>  
>  void update_cache_mode_entry(unsigned entry, enum page_cache_mode cache);
>  
> +extern bool sev_enabled __section(.data);

Lets move this into arch/x86/include/asm/mem_encrypt.h and then add
#include <linux/mem_encrypt.h> to mem_encrypt_identity.c.

Thanks,
Tom

>  #endif	/* __X86_MM_INTERNAL_H */
> 

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Re: [PATCHv3 1/3] x86/mm/encrypt: Move page table helpers into separate translation unit

[Kirill A. Shutemov]

On Tue, Jan 30, 2018 at 04:26:03PM -0600, Tom Lendacky wrote:
> On 1/24/2018 10:36 AM, Kirill A. Shutemov wrote:
> > There are bunch of functions in mem_encrypt.c that operate on the
> > identity mapping, which means they want virtual addresses to be equal to
> > physical one, without PAGE_OFFSET shift.
> > 
> > We also need to avoid paravirtualizaion call there.
> > 
> > Getting this done is tricky. We cannot use usual page table helpers.
> > It forces us to open-code a lot of things. It makes code ugly and hard
> > to modify.
> > 
> > We can get it work with the page table helpers, but it requires few
> > preprocessor tricks. These tricks may have side effects for the rest of
> > the file.
> > 
> > Let's isolate such functions into own translation unit.
> > 
> > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> 
> Just one minor comment at the end.  With that change:
> 
> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
> 
> > ---
> >  arch/x86/mm/Makefile               |  14 +-
> >  arch/x86/mm/mem_encrypt.c          | 578 +----------------------------------
> >  arch/x86/mm/mem_encrypt_identity.c | 596 +++++++++++++++++++++++++++++++++++++
> >  arch/x86/mm/mm_internal.h          |   1 +
> >  4 files changed, 607 insertions(+), 582 deletions(-)
> >  create mode 100644 arch/x86/mm/mem_encrypt_identity.c
> > 
> 
> ...
> 
> > diff --git a/arch/x86/mm/mm_internal.h b/arch/x86/mm/mm_internal.h
> > index 4e1f6e1b8159..7b4fc4386d90 100644
> > --- a/arch/x86/mm/mm_internal.h
> > +++ b/arch/x86/mm/mm_internal.h
> > @@ -19,4 +19,5 @@ extern int after_bootmem;
> >  
> >  void update_cache_mode_entry(unsigned entry, enum page_cache_mode cache);
> >  
> > +extern bool sev_enabled __section(.data);
> 
> Lets move this into arch/x86/include/asm/mem_encrypt.h and then add
> #include <linux/mem_encrypt.h> to mem_encrypt_identity.c.

Why? Will we need it beyond arch/x86/mm/ in the future?

-- 
 Kirill A. Shutemov

Re: [PATCHv3 1/3] x86/mm/encrypt: Move page table helpers into separate translation unit

[Kirill A. Shutemov]

On Tue, Jan 30, 2018 at 04:26:03PM -0600, Tom Lendacky wrote:
> On 1/24/2018 10:36 AM, Kirill A. Shutemov wrote:
> > There are bunch of functions in mem_encrypt.c that operate on the
> > identity mapping, which means they want virtual addresses to be equal to
> > physical one, without PAGE_OFFSET shift.
> > 
> > We also need to avoid paravirtualizaion call there.
> > 
> > Getting this done is tricky. We cannot use usual page table helpers.
> > It forces us to open-code a lot of things. It makes code ugly and hard
> > to modify.
> > 
> > We can get it work with the page table helpers, but it requires few
> > preprocessor tricks. These tricks may have side effects for the rest of
> > the file.
> > 
> > Let's isolate such functions into own translation unit.
> > 
> > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> 
> Just one minor comment at the end.  With that change:
> 
> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
> 
> > ---
> >  arch/x86/mm/Makefile               |  14 +-
> >  arch/x86/mm/mem_encrypt.c          | 578 +----------------------------------
> >  arch/x86/mm/mem_encrypt_identity.c | 596 +++++++++++++++++++++++++++++++++++++
> >  arch/x86/mm/mm_internal.h          |   1 +
> >  4 files changed, 607 insertions(+), 582 deletions(-)
> >  create mode 100644 arch/x86/mm/mem_encrypt_identity.c
> > 
> 
> ...
> 
> > diff --git a/arch/x86/mm/mm_internal.h b/arch/x86/mm/mm_internal.h
> > index 4e1f6e1b8159..7b4fc4386d90 100644
> > --- a/arch/x86/mm/mm_internal.h
> > +++ b/arch/x86/mm/mm_internal.h
> > @@ -19,4 +19,5 @@ extern int after_bootmem;
> >  
> >  void update_cache_mode_entry(unsigned entry, enum page_cache_mode cache);
> >  
> > +extern bool sev_enabled __section(.data);
> 
> Lets move this into arch/x86/include/asm/mem_encrypt.h and then add
> #include <linux/mem_encrypt.h> to mem_encrypt_identity.c.

Why? Will we need it beyond arch/x86/mm/ in the future?

-- 
 Kirill A. Shutemov

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Re: [PATCHv3 1/3] x86/mm/encrypt: Move page table helpers into separate translation unit

[Tom Lendacky]

On 1/30/2018 4:28 PM, Kirill A. Shutemov wrote:
> On Tue, Jan 30, 2018 at 04:26:03PM -0600, Tom Lendacky wrote:
>> On 1/24/2018 10:36 AM, Kirill A. Shutemov wrote:
>>> There are bunch of functions in mem_encrypt.c that operate on the
>>> identity mapping, which means they want virtual addresses to be equal to
>>> physical one, without PAGE_OFFSET shift.
>>>
>>> We also need to avoid paravirtualizaion call there.
>>>
>>> Getting this done is tricky. We cannot use usual page table helpers.
>>> It forces us to open-code a lot of things. It makes code ugly and hard
>>> to modify.
>>>
>>> We can get it work with the page table helpers, but it requires few
>>> preprocessor tricks. These tricks may have side effects for the rest of
>>> the file.
>>>
>>> Let's isolate such functions into own translation unit.
>>>
>>> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
>>
>> Just one minor comment at the end.  With that change:
>>
>> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
>>
>>> ---
>>>  arch/x86/mm/Makefile               |  14 +-
>>>  arch/x86/mm/mem_encrypt.c          | 578 +----------------------------------
>>>  arch/x86/mm/mem_encrypt_identity.c | 596 +++++++++++++++++++++++++++++++++++++
>>>  arch/x86/mm/mm_internal.h          |   1 +
>>>  4 files changed, 607 insertions(+), 582 deletions(-)
>>>  create mode 100644 arch/x86/mm/mem_encrypt_identity.c
>>>
>>
>> ...
>>
>>> diff --git a/arch/x86/mm/mm_internal.h b/arch/x86/mm/mm_internal.h
>>> index 4e1f6e1b8159..7b4fc4386d90 100644
>>> --- a/arch/x86/mm/mm_internal.h
>>> +++ b/arch/x86/mm/mm_internal.h
>>> @@ -19,4 +19,5 @@ extern int after_bootmem;
>>>  
>>>  void update_cache_mode_entry(unsigned entry, enum page_cache_mode cache);
>>>  
>>> +extern bool sev_enabled __section(.data);
>>
>> Lets move this into arch/x86/include/asm/mem_encrypt.h and then add
>> #include <linux/mem_encrypt.h> to mem_encrypt_identity.c.
> 
> Why? Will we need it beyond arch/x86/mm/ in the future?

I just think it would be best to keep all the memory encryption stuff
together.

Thanks,
Tom

> 

Re: [PATCHv3 1/3] x86/mm/encrypt: Move page table helpers into separate translation unit

[Tom Lendacky]

On 1/30/2018 4:28 PM, Kirill A. Shutemov wrote:
> On Tue, Jan 30, 2018 at 04:26:03PM -0600, Tom Lendacky wrote:
>> On 1/24/2018 10:36 AM, Kirill A. Shutemov wrote:
>>> There are bunch of functions in mem_encrypt.c that operate on the
>>> identity mapping, which means they want virtual addresses to be equal to
>>> physical one, without PAGE_OFFSET shift.
>>>
>>> We also need to avoid paravirtualizaion call there.
>>>
>>> Getting this done is tricky. We cannot use usual page table helpers.
>>> It forces us to open-code a lot of things. It makes code ugly and hard
>>> to modify.
>>>
>>> We can get it work with the page table helpers, but it requires few
>>> preprocessor tricks. These tricks may have side effects for the rest of
>>> the file.
>>>
>>> Let's isolate such functions into own translation unit.
>>>
>>> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
>>
>> Just one minor comment at the end.  With that change:
>>
>> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
>>
>>> ---
>>>  arch/x86/mm/Makefile               |  14 +-
>>>  arch/x86/mm/mem_encrypt.c          | 578 +----------------------------------
>>>  arch/x86/mm/mem_encrypt_identity.c | 596 +++++++++++++++++++++++++++++++++++++
>>>  arch/x86/mm/mm_internal.h          |   1 +
>>>  4 files changed, 607 insertions(+), 582 deletions(-)
>>>  create mode 100644 arch/x86/mm/mem_encrypt_identity.c
>>>
>>
>> ...
>>
>>> diff --git a/arch/x86/mm/mm_internal.h b/arch/x86/mm/mm_internal.h
>>> index 4e1f6e1b8159..7b4fc4386d90 100644
>>> --- a/arch/x86/mm/mm_internal.h
>>> +++ b/arch/x86/mm/mm_internal.h
>>> @@ -19,4 +19,5 @@ extern int after_bootmem;
>>>  
>>>  void update_cache_mode_entry(unsigned entry, enum page_cache_mode cache);
>>>  
>>> +extern bool sev_enabled __section(.data);
>>
>> Lets move this into arch/x86/include/asm/mem_encrypt.h and then add
>> #include <linux/mem_encrypt.h> to mem_encrypt_identity.c.
> 
> Why? Will we need it beyond arch/x86/mm/ in the future?

I just think it would be best to keep all the memory encryption stuff
together.

Thanks,
Tom

> 

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[PATCHv3 2/3] x86/mm/encrypt: Rewrite sme_populate_pgd() and sme_populate_pgd_large()

[Kirill A. Shutemov]

sme_populate_pgd() and sme_populate_pgd_large() operate on the identity
mapping, which means they want virtual addresses to be equal to physical
one, without PAGE_OFFSET shift.

We also need to avoid paravirtualizaion call there.

Getting this done is tricky. We cannot use usual page table helpers.
It forces us to open-code a lot of things. It makes code ugly and hard
to modify.

We can get it work with the page table helpers, but it requires few
preprocessor tricks.

  - Define __pa() and __va() to be compatible with identity mapping.

  - Undef CONFIG_PARAVIRT and CONFIG_PARAVIRT_SPINLOCKS before including
    any file. This way we can avoid pearavirtualization calls.

Now we can user normal page table helpers just fine.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 arch/x86/mm/mem_encrypt_identity.c | 159 +++++++++++++++++--------------------
 1 file changed, 72 insertions(+), 87 deletions(-)

diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c
index c23d55cb25c4..69635a02ce9e 100644
--- a/arch/x86/mm/mem_encrypt_identity.c
+++ b/arch/x86/mm/mem_encrypt_identity.c
@@ -12,6 +12,24 @@
 
 #define DISABLE_BRANCH_PROFILING
 
+/*
+ * Since we're dealing with identity mappings, physical and virtual
+ * addresses are the same, so override these defines which are ultimately
+ * used by the headers in misc.h.
+ */
+#define __pa(x)  ((unsigned long)(x))
+#define __va(x)  ((void *)((unsigned long)(x)))
+
+/*
+ * Special hack: we have to be careful, because no indirections are
+ * allowed here, and paravirt_ops is a kind of one. As it will only run in
+ * baremetal anyway, we just keep it from happening. (This list needs to
+ * be extended when new paravirt and debugging variants are added.)
+ */
+#undef CONFIG_PARAVIRT
+#undef CONFIG_PARAVIRT_SPINLOCKS
+
+#include <linux/kernel.h>
 #include <linux/mm.h>
 
 #include <asm/setup.h>
@@ -72,116 +90,83 @@ static void __init sme_clear_pgd(struct sme_populate_pgd_data *ppd)
 	memset(pgd_p, 0, pgd_size);
 }
 
-static pmd_t __init *sme_prepare_pgd(struct sme_populate_pgd_data *ppd)
+static pud_t __init *sme_prepare_pgd(struct sme_populate_pgd_data *ppd)
 {
-	pgd_t *pgd_p;
-	p4d_t *p4d_p;
-	pud_t *pud_p;
-	pmd_t *pmd_p;
-
-	pgd_p = ppd->pgd + pgd_index(ppd->vaddr);
-	if (native_pgd_val(*pgd_p)) {
-		if (IS_ENABLED(CONFIG_X86_5LEVEL))
-			p4d_p = (p4d_t *)(native_pgd_val(*pgd_p) & ~PTE_FLAGS_MASK);
-		else
-			pud_p = (pud_t *)(native_pgd_val(*pgd_p) & ~PTE_FLAGS_MASK);
-	} else {
-		pgd_t pgd;
-
-		if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
-			p4d_p = ppd->pgtable_area;
-			memset(p4d_p, 0, sizeof(*p4d_p) * PTRS_PER_P4D);
-			ppd->pgtable_area += sizeof(*p4d_p) * PTRS_PER_P4D;
-
-			pgd = native_make_pgd((pgdval_t)p4d_p + PGD_FLAGS);
-		} else {
-			pud_p = ppd->pgtable_area;
-			memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
-			ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
-
-			pgd = native_make_pgd((pgdval_t)pud_p + PGD_FLAGS);
-		}
-		native_set_pgd(pgd_p, pgd);
+	pgd_t *pgd;
+	p4d_t *p4d;
+	pud_t *pud;
+	pmd_t *pmd;
+
+	pgd = ppd->pgd + pgd_index(ppd->vaddr);
+	if (pgd_none(*pgd)) {
+		p4d = ppd->pgtable_area;
+		memset(p4d, 0, sizeof(*p4d) * PTRS_PER_P4D);
+		ppd->pgtable_area += sizeof(*p4d) * PTRS_PER_P4D;
+		set_pgd(pgd, __pgd(PGD_FLAGS | __pa(p4d)));
 	}
 
-	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
-		p4d_p += p4d_index(ppd->vaddr);
-		if (native_p4d_val(*p4d_p)) {
-			pud_p = (pud_t *)(native_p4d_val(*p4d_p) & ~PTE_FLAGS_MASK);
-		} else {
-			p4d_t p4d;
-
-			pud_p = ppd->pgtable_area;
-			memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
-			ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
-
-			p4d = native_make_p4d((pudval_t)pud_p + P4D_FLAGS);
-			native_set_p4d(p4d_p, p4d);
-		}
+	p4d = p4d_offset(pgd, ppd->vaddr);
+	if (p4d_none(*p4d)) {
+		pud = ppd->pgtable_area;
+		memset(pud, 0, sizeof(*pud) * PTRS_PER_PUD);
+		ppd->pgtable_area += sizeof(*pud) * PTRS_PER_PUD;
+		set_p4d(p4d, __p4d(P4D_FLAGS | __pa(pud)));
 	}
 
-	pud_p += pud_index(ppd->vaddr);
-	if (native_pud_val(*pud_p)) {
-		if (native_pud_val(*pud_p) & _PAGE_PSE)
-			return NULL;
-
-		pmd_p = (pmd_t *)(native_pud_val(*pud_p) & ~PTE_FLAGS_MASK);
-	} else {
-		pud_t pud;
-
-		pmd_p = ppd->pgtable_area;
-		memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD);
-		ppd->pgtable_area += sizeof(*pmd_p) * PTRS_PER_PMD;
-
-		pud = native_make_pud((pmdval_t)pmd_p + PUD_FLAGS);
-		native_set_pud(pud_p, pud);
+	pud = pud_offset(p4d, ppd->vaddr);
+	if (pud_none(*pud)) {
+		pmd = ppd->pgtable_area;
+		memset(pmd, 0, sizeof(*pmd) * PTRS_PER_PMD);
+		ppd->pgtable_area += sizeof(*pmd) * PTRS_PER_PMD;
+		set_pud(pud, __pud(PUD_FLAGS | __pa(pmd)));
 	}
 
-	return pmd_p;
+	if (pud_large(*pud))
+		return NULL;
+
+	return pud;
 }
 
 static void __init sme_populate_pgd_large(struct sme_populate_pgd_data *ppd)
 {
-	pmd_t *pmd_p;
+	pud_t *pud;
+	pmd_t *pmd;
 
-	pmd_p = sme_prepare_pgd(ppd);
-	if (!pmd_p)
+	pud = sme_prepare_pgd(ppd);
+	if (!pud)
 		return;
 
-	pmd_p += pmd_index(ppd->vaddr);
-	if (!native_pmd_val(*pmd_p) || !(native_pmd_val(*pmd_p) & _PAGE_PSE))
-		native_set_pmd(pmd_p, native_make_pmd(ppd->paddr | ppd->pmd_flags));
+	pmd = pmd_offset(pud, ppd->vaddr);
+	if (pmd_large(*pmd))
+		return;
+
+	set_pmd(pmd, __pmd(ppd->paddr | ppd->pmd_flags));
 }
 
 static void __init sme_populate_pgd(struct sme_populate_pgd_data *ppd)
 {
-	pmd_t *pmd_p;
-	pte_t *pte_p;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte;
 
-	pmd_p = sme_prepare_pgd(ppd);
-	if (!pmd_p)
+	pud = sme_prepare_pgd(ppd);
+	if (!pud)
 		return;
 
-	pmd_p += pmd_index(ppd->vaddr);
-	if (native_pmd_val(*pmd_p)) {
-		if (native_pmd_val(*pmd_p) & _PAGE_PSE)
-			return;
-
-		pte_p = (pte_t *)(native_pmd_val(*pmd_p) & ~PTE_FLAGS_MASK);
-	} else {
-		pmd_t pmd;
-
-		pte_p = ppd->pgtable_area;
-		memset(pte_p, 0, sizeof(*pte_p) * PTRS_PER_PTE);
-		ppd->pgtable_area += sizeof(*pte_p) * PTRS_PER_PTE;
-
-		pmd = native_make_pmd((pteval_t)pte_p + PMD_FLAGS);
-		native_set_pmd(pmd_p, pmd);
+	pmd = pmd_offset(pud, ppd->vaddr);
+	if (pmd_none(*pmd)) {
+		pte = ppd->pgtable_area;
+		memset(pte, 0, sizeof(pte) * PTRS_PER_PTE);
+		ppd->pgtable_area += sizeof(pte) * PTRS_PER_PTE;
+		set_pmd(pmd, __pmd(PMD_FLAGS | __pa(pte)));
 	}
 
-	pte_p += pte_index(ppd->vaddr);
-	if (!native_pte_val(*pte_p))
-		native_set_pte(pte_p, native_make_pte(ppd->paddr | ppd->pte_flags));
+	if (pmd_large(*pmd))
+		return;
+
+	pte = pte_offset_map(pmd, ppd->vaddr);
+	if (pte_none(*pte))
+		set_pte(pte, __pte(ppd->paddr | ppd->pte_flags));
 }
 
 static void __init __sme_map_range_pmd(struct sme_populate_pgd_data *ppd)
-- 
2.15.1

[PATCHv3 2/3] x86/mm/encrypt: Rewrite sme_populate_pgd() and sme_populate_pgd_large()

[Kirill A. Shutemov]

sme_populate_pgd() and sme_populate_pgd_large() operate on the identity
mapping, which means they want virtual addresses to be equal to physical
one, without PAGE_OFFSET shift.

We also need to avoid paravirtualizaion call there.

Getting this done is tricky. We cannot use usual page table helpers.
It forces us to open-code a lot of things. It makes code ugly and hard
to modify.

We can get it work with the page table helpers, but it requires few
preprocessor tricks.

  - Define __pa() and __va() to be compatible with identity mapping.

  - Undef CONFIG_PARAVIRT and CONFIG_PARAVIRT_SPINLOCKS before including
    any file. This way we can avoid pearavirtualization calls.

Now we can user normal page table helpers just fine.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 arch/x86/mm/mem_encrypt_identity.c | 159 +++++++++++++++++--------------------
 1 file changed, 72 insertions(+), 87 deletions(-)

diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c
index c23d55cb25c4..69635a02ce9e 100644
--- a/arch/x86/mm/mem_encrypt_identity.c
+++ b/arch/x86/mm/mem_encrypt_identity.c
@@ -12,6 +12,24 @@
 
 #define DISABLE_BRANCH_PROFILING
 
+/*
+ * Since we're dealing with identity mappings, physical and virtual
+ * addresses are the same, so override these defines which are ultimately
+ * used by the headers in misc.h.
+ */
+#define __pa(x)  ((unsigned long)(x))
+#define __va(x)  ((void *)((unsigned long)(x)))
+
+/*
+ * Special hack: we have to be careful, because no indirections are
+ * allowed here, and paravirt_ops is a kind of one. As it will only run in
+ * baremetal anyway, we just keep it from happening. (This list needs to
+ * be extended when new paravirt and debugging variants are added.)
+ */
+#undef CONFIG_PARAVIRT
+#undef CONFIG_PARAVIRT_SPINLOCKS
+
+#include <linux/kernel.h>
 #include <linux/mm.h>
 
 #include <asm/setup.h>
@@ -72,116 +90,83 @@ static void __init sme_clear_pgd(struct sme_populate_pgd_data *ppd)
 	memset(pgd_p, 0, pgd_size);
 }
 
-static pmd_t __init *sme_prepare_pgd(struct sme_populate_pgd_data *ppd)
+static pud_t __init *sme_prepare_pgd(struct sme_populate_pgd_data *ppd)
 {
-	pgd_t *pgd_p;
-	p4d_t *p4d_p;
-	pud_t *pud_p;
-	pmd_t *pmd_p;
-
-	pgd_p = ppd->pgd + pgd_index(ppd->vaddr);
-	if (native_pgd_val(*pgd_p)) {
-		if (IS_ENABLED(CONFIG_X86_5LEVEL))
-			p4d_p = (p4d_t *)(native_pgd_val(*pgd_p) & ~PTE_FLAGS_MASK);
-		else
-			pud_p = (pud_t *)(native_pgd_val(*pgd_p) & ~PTE_FLAGS_MASK);
-	} else {
-		pgd_t pgd;
-
-		if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
-			p4d_p = ppd->pgtable_area;
-			memset(p4d_p, 0, sizeof(*p4d_p) * PTRS_PER_P4D);
-			ppd->pgtable_area += sizeof(*p4d_p) * PTRS_PER_P4D;
-
-			pgd = native_make_pgd((pgdval_t)p4d_p + PGD_FLAGS);
-		} else {
-			pud_p = ppd->pgtable_area;
-			memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
-			ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
-
-			pgd = native_make_pgd((pgdval_t)pud_p + PGD_FLAGS);
-		}
-		native_set_pgd(pgd_p, pgd);
+	pgd_t *pgd;
+	p4d_t *p4d;
+	pud_t *pud;
+	pmd_t *pmd;
+
+	pgd = ppd->pgd + pgd_index(ppd->vaddr);
+	if (pgd_none(*pgd)) {
+		p4d = ppd->pgtable_area;
+		memset(p4d, 0, sizeof(*p4d) * PTRS_PER_P4D);
+		ppd->pgtable_area += sizeof(*p4d) * PTRS_PER_P4D;
+		set_pgd(pgd, __pgd(PGD_FLAGS | __pa(p4d)));
 	}
 
-	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
-		p4d_p += p4d_index(ppd->vaddr);
-		if (native_p4d_val(*p4d_p)) {
-			pud_p = (pud_t *)(native_p4d_val(*p4d_p) & ~PTE_FLAGS_MASK);
-		} else {
-			p4d_t p4d;
-
-			pud_p = ppd->pgtable_area;
-			memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
-			ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
-
-			p4d = native_make_p4d((pudval_t)pud_p + P4D_FLAGS);
-			native_set_p4d(p4d_p, p4d);
-		}
+	p4d = p4d_offset(pgd, ppd->vaddr);
+	if (p4d_none(*p4d)) {
+		pud = ppd->pgtable_area;
+		memset(pud, 0, sizeof(*pud) * PTRS_PER_PUD);
+		ppd->pgtable_area += sizeof(*pud) * PTRS_PER_PUD;
+		set_p4d(p4d, __p4d(P4D_FLAGS | __pa(pud)));
 	}
 
-	pud_p += pud_index(ppd->vaddr);
-	if (native_pud_val(*pud_p)) {
-		if (native_pud_val(*pud_p) & _PAGE_PSE)
-			return NULL;
-
-		pmd_p = (pmd_t *)(native_pud_val(*pud_p) & ~PTE_FLAGS_MASK);
-	} else {
-		pud_t pud;
-
-		pmd_p = ppd->pgtable_area;
-		memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD);
-		ppd->pgtable_area += sizeof(*pmd_p) * PTRS_PER_PMD;
-
-		pud = native_make_pud((pmdval_t)pmd_p + PUD_FLAGS);
-		native_set_pud(pud_p, pud);
+	pud = pud_offset(p4d, ppd->vaddr);
+	if (pud_none(*pud)) {
+		pmd = ppd->pgtable_area;
+		memset(pmd, 0, sizeof(*pmd) * PTRS_PER_PMD);
+		ppd->pgtable_area += sizeof(*pmd) * PTRS_PER_PMD;
+		set_pud(pud, __pud(PUD_FLAGS | __pa(pmd)));
 	}
 
-	return pmd_p;
+	if (pud_large(*pud))
+		return NULL;
+
+	return pud;
 }
 
 static void __init sme_populate_pgd_large(struct sme_populate_pgd_data *ppd)
 {
-	pmd_t *pmd_p;
+	pud_t *pud;
+	pmd_t *pmd;
 
-	pmd_p = sme_prepare_pgd(ppd);
-	if (!pmd_p)
+	pud = sme_prepare_pgd(ppd);
+	if (!pud)
 		return;
 
-	pmd_p += pmd_index(ppd->vaddr);
-	if (!native_pmd_val(*pmd_p) || !(native_pmd_val(*pmd_p) & _PAGE_PSE))
-		native_set_pmd(pmd_p, native_make_pmd(ppd->paddr | ppd->pmd_flags));
+	pmd = pmd_offset(pud, ppd->vaddr);
+	if (pmd_large(*pmd))
+		return;
+
+	set_pmd(pmd, __pmd(ppd->paddr | ppd->pmd_flags));
 }
 
 static void __init sme_populate_pgd(struct sme_populate_pgd_data *ppd)
 {
-	pmd_t *pmd_p;
-	pte_t *pte_p;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte;
 
-	pmd_p = sme_prepare_pgd(ppd);
-	if (!pmd_p)
+	pud = sme_prepare_pgd(ppd);
+	if (!pud)
 		return;
 
-	pmd_p += pmd_index(ppd->vaddr);
-	if (native_pmd_val(*pmd_p)) {
-		if (native_pmd_val(*pmd_p) & _PAGE_PSE)
-			return;
-
-		pte_p = (pte_t *)(native_pmd_val(*pmd_p) & ~PTE_FLAGS_MASK);
-	} else {
-		pmd_t pmd;
-
-		pte_p = ppd->pgtable_area;
-		memset(pte_p, 0, sizeof(*pte_p) * PTRS_PER_PTE);
-		ppd->pgtable_area += sizeof(*pte_p) * PTRS_PER_PTE;
-
-		pmd = native_make_pmd((pteval_t)pte_p + PMD_FLAGS);
-		native_set_pmd(pmd_p, pmd);
+	pmd = pmd_offset(pud, ppd->vaddr);
+	if (pmd_none(*pmd)) {
+		pte = ppd->pgtable_area;
+		memset(pte, 0, sizeof(pte) * PTRS_PER_PTE);
+		ppd->pgtable_area += sizeof(pte) * PTRS_PER_PTE;
+		set_pmd(pmd, __pmd(PMD_FLAGS | __pa(pte)));
 	}
 
-	pte_p += pte_index(ppd->vaddr);
-	if (!native_pte_val(*pte_p))
-		native_set_pte(pte_p, native_make_pte(ppd->paddr | ppd->pte_flags));
+	if (pmd_large(*pmd))
+		return;
+
+	pte = pte_offset_map(pmd, ppd->vaddr);
+	if (pte_none(*pte))
+		set_pte(pte, __pte(ppd->paddr | ppd->pte_flags));
 }
 
 static void __init __sme_map_range_pmd(struct sme_populate_pgd_data *ppd)
-- 
2.15.1

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Re: [PATCHv3 2/3] x86/mm/encrypt: Rewrite sme_populate_pgd() and sme_populate_pgd_large()

[Tom Lendacky]

On 1/24/2018 10:36 AM, Kirill A. Shutemov wrote:
> sme_populate_pgd() and sme_populate_pgd_large() operate on the identity
> mapping, which means they want virtual addresses to be equal to physical
> one, without PAGE_OFFSET shift.
> 
> We also need to avoid paravirtualizaion call there.

paravirtualization

> 
> Getting this done is tricky. We cannot use usual page table helpers.
> It forces us to open-code a lot of things. It makes code ugly and hard
> to modify.
> 
> We can get it work with the page table helpers, but it requires few
> preprocessor tricks.
> 
>   - Define __pa() and __va() to be compatible with identity mapping.
> 
>   - Undef CONFIG_PARAVIRT and CONFIG_PARAVIRT_SPINLOCKS before including
>     any file. This way we can avoid pearavirtualization calls.

paravirtualization

> 
> Now we can user normal page table helpers just fine.
> 
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>

Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>

> ---
>  arch/x86/mm/mem_encrypt_identity.c | 159 +++++++++++++++++--------------------
>  1 file changed, 72 insertions(+), 87 deletions(-)
> 
> diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c
> index c23d55cb25c4..69635a02ce9e 100644
> --- a/arch/x86/mm/mem_encrypt_identity.c
> +++ b/arch/x86/mm/mem_encrypt_identity.c
> @@ -12,6 +12,24 @@
>  
>  #define DISABLE_BRANCH_PROFILING
>  
> +/*
> + * Since we're dealing with identity mappings, physical and virtual
> + * addresses are the same, so override these defines which are ultimately
> + * used by the headers in misc.h.
> + */
> +#define __pa(x)  ((unsigned long)(x))
> +#define __va(x)  ((void *)((unsigned long)(x)))
> +
> +/*
> + * Special hack: we have to be careful, because no indirections are
> + * allowed here, and paravirt_ops is a kind of one. As it will only run in
> + * baremetal anyway, we just keep it from happening. (This list needs to
> + * be extended when new paravirt and debugging variants are added.)
> + */
> +#undef CONFIG_PARAVIRT
> +#undef CONFIG_PARAVIRT_SPINLOCKS
> +
> +#include <linux/kernel.h>
>  #include <linux/mm.h>
>  
>  #include <asm/setup.h>
> @@ -72,116 +90,83 @@ static void __init sme_clear_pgd(struct sme_populate_pgd_data *ppd)
>  	memset(pgd_p, 0, pgd_size);
>  }
>  
> -static pmd_t __init *sme_prepare_pgd(struct sme_populate_pgd_data *ppd)
> +static pud_t __init *sme_prepare_pgd(struct sme_populate_pgd_data *ppd)
>  {
> -	pgd_t *pgd_p;
> -	p4d_t *p4d_p;
> -	pud_t *pud_p;
> -	pmd_t *pmd_p;
> -
> -	pgd_p = ppd->pgd + pgd_index(ppd->vaddr);
> -	if (native_pgd_val(*pgd_p)) {
> -		if (IS_ENABLED(CONFIG_X86_5LEVEL))
> -			p4d_p = (p4d_t *)(native_pgd_val(*pgd_p) & ~PTE_FLAGS_MASK);
> -		else
> -			pud_p = (pud_t *)(native_pgd_val(*pgd_p) & ~PTE_FLAGS_MASK);
> -	} else {
> -		pgd_t pgd;
> -
> -		if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
> -			p4d_p = ppd->pgtable_area;
> -			memset(p4d_p, 0, sizeof(*p4d_p) * PTRS_PER_P4D);
> -			ppd->pgtable_area += sizeof(*p4d_p) * PTRS_PER_P4D;
> -
> -			pgd = native_make_pgd((pgdval_t)p4d_p + PGD_FLAGS);
> -		} else {
> -			pud_p = ppd->pgtable_area;
> -			memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
> -			ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
> -
> -			pgd = native_make_pgd((pgdval_t)pud_p + PGD_FLAGS);
> -		}
> -		native_set_pgd(pgd_p, pgd);
> +	pgd_t *pgd;
> +	p4d_t *p4d;
> +	pud_t *pud;
> +	pmd_t *pmd;
> +
> +	pgd = ppd->pgd + pgd_index(ppd->vaddr);
> +	if (pgd_none(*pgd)) {
> +		p4d = ppd->pgtable_area;
> +		memset(p4d, 0, sizeof(*p4d) * PTRS_PER_P4D);
> +		ppd->pgtable_area += sizeof(*p4d) * PTRS_PER_P4D;
> +		set_pgd(pgd, __pgd(PGD_FLAGS | __pa(p4d)));
>  	}
>  
> -	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
> -		p4d_p += p4d_index(ppd->vaddr);
> -		if (native_p4d_val(*p4d_p)) {
> -			pud_p = (pud_t *)(native_p4d_val(*p4d_p) & ~PTE_FLAGS_MASK);
> -		} else {
> -			p4d_t p4d;
> -
> -			pud_p = ppd->pgtable_area;
> -			memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
> -			ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
> -
> -			p4d = native_make_p4d((pudval_t)pud_p + P4D_FLAGS);
> -			native_set_p4d(p4d_p, p4d);
> -		}
> +	p4d = p4d_offset(pgd, ppd->vaddr);
> +	if (p4d_none(*p4d)) {
> +		pud = ppd->pgtable_area;
> +		memset(pud, 0, sizeof(*pud) * PTRS_PER_PUD);
> +		ppd->pgtable_area += sizeof(*pud) * PTRS_PER_PUD;
> +		set_p4d(p4d, __p4d(P4D_FLAGS | __pa(pud)));
>  	}
>  
> -	pud_p += pud_index(ppd->vaddr);
> -	if (native_pud_val(*pud_p)) {
> -		if (native_pud_val(*pud_p) & _PAGE_PSE)
> -			return NULL;
> -
> -		pmd_p = (pmd_t *)(native_pud_val(*pud_p) & ~PTE_FLAGS_MASK);
> -	} else {
> -		pud_t pud;
> -
> -		pmd_p = ppd->pgtable_area;
> -		memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD);
> -		ppd->pgtable_area += sizeof(*pmd_p) * PTRS_PER_PMD;
> -
> -		pud = native_make_pud((pmdval_t)pmd_p + PUD_FLAGS);
> -		native_set_pud(pud_p, pud);
> +	pud = pud_offset(p4d, ppd->vaddr);
> +	if (pud_none(*pud)) {
> +		pmd = ppd->pgtable_area;
> +		memset(pmd, 0, sizeof(*pmd) * PTRS_PER_PMD);
> +		ppd->pgtable_area += sizeof(*pmd) * PTRS_PER_PMD;
> +		set_pud(pud, __pud(PUD_FLAGS | __pa(pmd)));
>  	}
>  
> -	return pmd_p;
> +	if (pud_large(*pud))
> +		return NULL;
> +
> +	return pud;
>  }
>  
>  static void __init sme_populate_pgd_large(struct sme_populate_pgd_data *ppd)
>  {
> -	pmd_t *pmd_p;
> +	pud_t *pud;
> +	pmd_t *pmd;
>  
> -	pmd_p = sme_prepare_pgd(ppd);
> -	if (!pmd_p)
> +	pud = sme_prepare_pgd(ppd);
> +	if (!pud)
>  		return;
>  
> -	pmd_p += pmd_index(ppd->vaddr);
> -	if (!native_pmd_val(*pmd_p) || !(native_pmd_val(*pmd_p) & _PAGE_PSE))
> -		native_set_pmd(pmd_p, native_make_pmd(ppd->paddr | ppd->pmd_flags));
> +	pmd = pmd_offset(pud, ppd->vaddr);
> +	if (pmd_large(*pmd))
> +		return;
> +
> +	set_pmd(pmd, __pmd(ppd->paddr | ppd->pmd_flags));
>  }
>  
>  static void __init sme_populate_pgd(struct sme_populate_pgd_data *ppd)
>  {
> -	pmd_t *pmd_p;
> -	pte_t *pte_p;
> +	pud_t *pud;
> +	pmd_t *pmd;
> +	pte_t *pte;
>  
> -	pmd_p = sme_prepare_pgd(ppd);
> -	if (!pmd_p)
> +	pud = sme_prepare_pgd(ppd);
> +	if (!pud)
>  		return;
>  
> -	pmd_p += pmd_index(ppd->vaddr);
> -	if (native_pmd_val(*pmd_p)) {
> -		if (native_pmd_val(*pmd_p) & _PAGE_PSE)
> -			return;
> -
> -		pte_p = (pte_t *)(native_pmd_val(*pmd_p) & ~PTE_FLAGS_MASK);
> -	} else {
> -		pmd_t pmd;
> -
> -		pte_p = ppd->pgtable_area;
> -		memset(pte_p, 0, sizeof(*pte_p) * PTRS_PER_PTE);
> -		ppd->pgtable_area += sizeof(*pte_p) * PTRS_PER_PTE;
> -
> -		pmd = native_make_pmd((pteval_t)pte_p + PMD_FLAGS);
> -		native_set_pmd(pmd_p, pmd);
> +	pmd = pmd_offset(pud, ppd->vaddr);
> +	if (pmd_none(*pmd)) {
> +		pte = ppd->pgtable_area;
> +		memset(pte, 0, sizeof(pte) * PTRS_PER_PTE);
> +		ppd->pgtable_area += sizeof(pte) * PTRS_PER_PTE;
> +		set_pmd(pmd, __pmd(PMD_FLAGS | __pa(pte)));
>  	}
>  
> -	pte_p += pte_index(ppd->vaddr);
> -	if (!native_pte_val(*pte_p))
> -		native_set_pte(pte_p, native_make_pte(ppd->paddr | ppd->pte_flags));
> +	if (pmd_large(*pmd))
> +		return;
> +
> +	pte = pte_offset_map(pmd, ppd->vaddr);
> +	if (pte_none(*pte))
> +		set_pte(pte, __pte(ppd->paddr | ppd->pte_flags));
>  }
>  
>  static void __init __sme_map_range_pmd(struct sme_populate_pgd_data *ppd)
> 

Re: [PATCHv3 2/3] x86/mm/encrypt: Rewrite sme_populate_pgd() and sme_populate_pgd_large()

[Tom Lendacky]

On 1/24/2018 10:36 AM, Kirill A. Shutemov wrote:
> sme_populate_pgd() and sme_populate_pgd_large() operate on the identity
> mapping, which means they want virtual addresses to be equal to physical
> one, without PAGE_OFFSET shift.
> 
> We also need to avoid paravirtualizaion call there.

paravirtualization

> 
> Getting this done is tricky. We cannot use usual page table helpers.
> It forces us to open-code a lot of things. It makes code ugly and hard
> to modify.
> 
> We can get it work with the page table helpers, but it requires few
> preprocessor tricks.
> 
>   - Define __pa() and __va() to be compatible with identity mapping.
> 
>   - Undef CONFIG_PARAVIRT and CONFIG_PARAVIRT_SPINLOCKS before including
>     any file. This way we can avoid pearavirtualization calls.

paravirtualization

> 
> Now we can user normal page table helpers just fine.
> 
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>

Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>

> ---
>  arch/x86/mm/mem_encrypt_identity.c | 159 +++++++++++++++++--------------------
>  1 file changed, 72 insertions(+), 87 deletions(-)
> 
> diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c
> index c23d55cb25c4..69635a02ce9e 100644
> --- a/arch/x86/mm/mem_encrypt_identity.c
> +++ b/arch/x86/mm/mem_encrypt_identity.c
> @@ -12,6 +12,24 @@
>  
>  #define DISABLE_BRANCH_PROFILING
>  
> +/*
> + * Since we're dealing with identity mappings, physical and virtual
> + * addresses are the same, so override these defines which are ultimately
> + * used by the headers in misc.h.
> + */
> +#define __pa(x)  ((unsigned long)(x))
> +#define __va(x)  ((void *)((unsigned long)(x)))
> +
> +/*
> + * Special hack: we have to be careful, because no indirections are
> + * allowed here, and paravirt_ops is a kind of one. As it will only run in
> + * baremetal anyway, we just keep it from happening. (This list needs to
> + * be extended when new paravirt and debugging variants are added.)
> + */
> +#undef CONFIG_PARAVIRT
> +#undef CONFIG_PARAVIRT_SPINLOCKS
> +
> +#include <linux/kernel.h>
>  #include <linux/mm.h>
>  
>  #include <asm/setup.h>
> @@ -72,116 +90,83 @@ static void __init sme_clear_pgd(struct sme_populate_pgd_data *ppd)
>  	memset(pgd_p, 0, pgd_size);
>  }
>  
> -static pmd_t __init *sme_prepare_pgd(struct sme_populate_pgd_data *ppd)
> +static pud_t __init *sme_prepare_pgd(struct sme_populate_pgd_data *ppd)
>  {
> -	pgd_t *pgd_p;
> -	p4d_t *p4d_p;
> -	pud_t *pud_p;
> -	pmd_t *pmd_p;
> -
> -	pgd_p = ppd->pgd + pgd_index(ppd->vaddr);
> -	if (native_pgd_val(*pgd_p)) {
> -		if (IS_ENABLED(CONFIG_X86_5LEVEL))
> -			p4d_p = (p4d_t *)(native_pgd_val(*pgd_p) & ~PTE_FLAGS_MASK);
> -		else
> -			pud_p = (pud_t *)(native_pgd_val(*pgd_p) & ~PTE_FLAGS_MASK);
> -	} else {
> -		pgd_t pgd;
> -
> -		if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
> -			p4d_p = ppd->pgtable_area;
> -			memset(p4d_p, 0, sizeof(*p4d_p) * PTRS_PER_P4D);
> -			ppd->pgtable_area += sizeof(*p4d_p) * PTRS_PER_P4D;
> -
> -			pgd = native_make_pgd((pgdval_t)p4d_p + PGD_FLAGS);
> -		} else {
> -			pud_p = ppd->pgtable_area;
> -			memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
> -			ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
> -
> -			pgd = native_make_pgd((pgdval_t)pud_p + PGD_FLAGS);
> -		}
> -		native_set_pgd(pgd_p, pgd);
> +	pgd_t *pgd;
> +	p4d_t *p4d;
> +	pud_t *pud;
> +	pmd_t *pmd;
> +
> +	pgd = ppd->pgd + pgd_index(ppd->vaddr);
> +	if (pgd_none(*pgd)) {
> +		p4d = ppd->pgtable_area;
> +		memset(p4d, 0, sizeof(*p4d) * PTRS_PER_P4D);
> +		ppd->pgtable_area += sizeof(*p4d) * PTRS_PER_P4D;
> +		set_pgd(pgd, __pgd(PGD_FLAGS | __pa(p4d)));
>  	}
>  
> -	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
> -		p4d_p += p4d_index(ppd->vaddr);
> -		if (native_p4d_val(*p4d_p)) {
> -			pud_p = (pud_t *)(native_p4d_val(*p4d_p) & ~PTE_FLAGS_MASK);
> -		} else {
> -			p4d_t p4d;
> -
> -			pud_p = ppd->pgtable_area;
> -			memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
> -			ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
> -
> -			p4d = native_make_p4d((pudval_t)pud_p + P4D_FLAGS);
> -			native_set_p4d(p4d_p, p4d);
> -		}
> +	p4d = p4d_offset(pgd, ppd->vaddr);
> +	if (p4d_none(*p4d)) {
> +		pud = ppd->pgtable_area;
> +		memset(pud, 0, sizeof(*pud) * PTRS_PER_PUD);
> +		ppd->pgtable_area += sizeof(*pud) * PTRS_PER_PUD;
> +		set_p4d(p4d, __p4d(P4D_FLAGS | __pa(pud)));
>  	}
>  
> -	pud_p += pud_index(ppd->vaddr);
> -	if (native_pud_val(*pud_p)) {
> -		if (native_pud_val(*pud_p) & _PAGE_PSE)
> -			return NULL;
> -
> -		pmd_p = (pmd_t *)(native_pud_val(*pud_p) & ~PTE_FLAGS_MASK);
> -	} else {
> -		pud_t pud;
> -
> -		pmd_p = ppd->pgtable_area;
> -		memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD);
> -		ppd->pgtable_area += sizeof(*pmd_p) * PTRS_PER_PMD;
> -
> -		pud = native_make_pud((pmdval_t)pmd_p + PUD_FLAGS);
> -		native_set_pud(pud_p, pud);
> +	pud = pud_offset(p4d, ppd->vaddr);
> +	if (pud_none(*pud)) {
> +		pmd = ppd->pgtable_area;
> +		memset(pmd, 0, sizeof(*pmd) * PTRS_PER_PMD);
> +		ppd->pgtable_area += sizeof(*pmd) * PTRS_PER_PMD;
> +		set_pud(pud, __pud(PUD_FLAGS | __pa(pmd)));
>  	}
>  
> -	return pmd_p;
> +	if (pud_large(*pud))
> +		return NULL;
> +
> +	return pud;
>  }
>  
>  static void __init sme_populate_pgd_large(struct sme_populate_pgd_data *ppd)
>  {
> -	pmd_t *pmd_p;
> +	pud_t *pud;
> +	pmd_t *pmd;
>  
> -	pmd_p = sme_prepare_pgd(ppd);
> -	if (!pmd_p)
> +	pud = sme_prepare_pgd(ppd);
> +	if (!pud)
>  		return;
>  
> -	pmd_p += pmd_index(ppd->vaddr);
> -	if (!native_pmd_val(*pmd_p) || !(native_pmd_val(*pmd_p) & _PAGE_PSE))
> -		native_set_pmd(pmd_p, native_make_pmd(ppd->paddr | ppd->pmd_flags));
> +	pmd = pmd_offset(pud, ppd->vaddr);
> +	if (pmd_large(*pmd))
> +		return;
> +
> +	set_pmd(pmd, __pmd(ppd->paddr | ppd->pmd_flags));
>  }
>  
>  static void __init sme_populate_pgd(struct sme_populate_pgd_data *ppd)
>  {
> -	pmd_t *pmd_p;
> -	pte_t *pte_p;
> +	pud_t *pud;
> +	pmd_t *pmd;
> +	pte_t *pte;
>  
> -	pmd_p = sme_prepare_pgd(ppd);
> -	if (!pmd_p)
> +	pud = sme_prepare_pgd(ppd);
> +	if (!pud)
>  		return;
>  
> -	pmd_p += pmd_index(ppd->vaddr);
> -	if (native_pmd_val(*pmd_p)) {
> -		if (native_pmd_val(*pmd_p) & _PAGE_PSE)
> -			return;
> -
> -		pte_p = (pte_t *)(native_pmd_val(*pmd_p) & ~PTE_FLAGS_MASK);
> -	} else {
> -		pmd_t pmd;
> -
> -		pte_p = ppd->pgtable_area;
> -		memset(pte_p, 0, sizeof(*pte_p) * PTRS_PER_PTE);
> -		ppd->pgtable_area += sizeof(*pte_p) * PTRS_PER_PTE;
> -
> -		pmd = native_make_pmd((pteval_t)pte_p + PMD_FLAGS);
> -		native_set_pmd(pmd_p, pmd);
> +	pmd = pmd_offset(pud, ppd->vaddr);
> +	if (pmd_none(*pmd)) {
> +		pte = ppd->pgtable_area;
> +		memset(pte, 0, sizeof(pte) * PTRS_PER_PTE);
> +		ppd->pgtable_area += sizeof(pte) * PTRS_PER_PTE;
> +		set_pmd(pmd, __pmd(PMD_FLAGS | __pa(pte)));
>  	}
>  
> -	pte_p += pte_index(ppd->vaddr);
> -	if (!native_pte_val(*pte_p))
> -		native_set_pte(pte_p, native_make_pte(ppd->paddr | ppd->pte_flags));
> +	if (pmd_large(*pmd))
> +		return;
> +
> +	pte = pte_offset_map(pmd, ppd->vaddr);
> +	if (pte_none(*pte))
> +		set_pte(pte, __pte(ppd->paddr | ppd->pte_flags));
>  }
>  
>  static void __init __sme_map_range_pmd(struct sme_populate_pgd_data *ppd)
> 

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[PATCHv3 3/3] x86/mm/encrypt: Rewrite sme_pgtable_calc()

[Kirill A. Shutemov]

sme_pgtable_calc() is unnecessary complex. It can be re-written in a
more stream-lined way.

As a side effect, we would get the code ready to boot-time switching
between paging modes.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 arch/x86/mm/mem_encrypt_identity.c | 42 +++++++++++---------------------------
 1 file changed, 12 insertions(+), 30 deletions(-)

diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c
index 69635a02ce9e..613686cc56ae 100644
--- a/arch/x86/mm/mem_encrypt_identity.c
+++ b/arch/x86/mm/mem_encrypt_identity.c
@@ -230,8 +230,7 @@ static void __init sme_map_range_decrypted_wp(struct sme_populate_pgd_data *ppd)
 
 static unsigned long __init sme_pgtable_calc(unsigned long len)
 {
-	unsigned long p4d_size, pud_size, pmd_size, pte_size;
-	unsigned long total;
+	unsigned long entries = 0, tables = 0;
 
 	/*
 	 * Perform a relatively simplistic calculation of the pagetable
@@ -245,42 +244,25 @@ static unsigned long __init sme_pgtable_calc(unsigned long len)
 	 * Incrementing the count for each covers the case where the addresses
 	 * cross entries.
 	 */
-	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
-		p4d_size = (ALIGN(len, PGDIR_SIZE) / PGDIR_SIZE) + 1;
-		p4d_size *= sizeof(p4d_t) * PTRS_PER_P4D;
-		pud_size = (ALIGN(len, P4D_SIZE) / P4D_SIZE) + 1;
-		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
-	} else {
-		p4d_size = 0;
-		pud_size = (ALIGN(len, PGDIR_SIZE) / PGDIR_SIZE) + 1;
-		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
-	}
-	pmd_size = (ALIGN(len, PUD_SIZE) / PUD_SIZE) + 1;
-	pmd_size *= sizeof(pmd_t) * PTRS_PER_PMD;
-	pte_size = 2 * sizeof(pte_t) * PTRS_PER_PTE;
 
-	total = p4d_size + pud_size + pmd_size + pte_size;
+	/* PGDIR_SIZE is equal to P4D_SIZE on 4-level machine. */
+	if (PTRS_PER_P4D > 1)
+		entries += (DIV_ROUND_UP(len, PGDIR_SIZE) + 1) * sizeof(p4d_t) * PTRS_PER_P4D;
+	entries += (DIV_ROUND_UP(len, P4D_SIZE) + 1) * sizeof(pud_t) * PTRS_PER_PUD;
+	entries += (DIV_ROUND_UP(len, PUD_SIZE) + 1) * sizeof(pmd_t) * PTRS_PER_PMD;
+	entries += 2 * sizeof(pte_t) * PTRS_PER_PTE;
 
 	/*
 	 * Now calculate the added pagetable structures needed to populate
 	 * the new pagetables.
 	 */
-	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
-		p4d_size = ALIGN(total, PGDIR_SIZE) / PGDIR_SIZE;
-		p4d_size *= sizeof(p4d_t) * PTRS_PER_P4D;
-		pud_size = ALIGN(total, P4D_SIZE) / P4D_SIZE;
-		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
-	} else {
-		p4d_size = 0;
-		pud_size = ALIGN(total, PGDIR_SIZE) / PGDIR_SIZE;
-		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
-	}
-	pmd_size = ALIGN(total, PUD_SIZE) / PUD_SIZE;
-	pmd_size *= sizeof(pmd_t) * PTRS_PER_PMD;
 
-	total += p4d_size + pud_size + pmd_size;
+	if (PTRS_PER_P4D > 1)
+		tables += DIV_ROUND_UP(entries, PGDIR_SIZE) * sizeof(p4d_t) * PTRS_PER_P4D;
+	tables += DIV_ROUND_UP(entries, P4D_SIZE) * sizeof(pud_t) * PTRS_PER_PUD;
+	tables += DIV_ROUND_UP(entries, PUD_SIZE) * sizeof(pmd_t) * PTRS_PER_PMD;
 
-	return total;
+	return entries + tables;
 }
 
 void __init __nostackprotector sme_encrypt_kernel(struct boot_params *bp)
-- 
2.15.1

[PATCHv3 3/3] x86/mm/encrypt: Rewrite sme_pgtable_calc()

[Kirill A. Shutemov]

sme_pgtable_calc() is unnecessary complex. It can be re-written in a
more stream-lined way.

As a side effect, we would get the code ready to boot-time switching
between paging modes.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 arch/x86/mm/mem_encrypt_identity.c | 42 +++++++++++---------------------------
 1 file changed, 12 insertions(+), 30 deletions(-)

diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c
index 69635a02ce9e..613686cc56ae 100644
--- a/arch/x86/mm/mem_encrypt_identity.c
+++ b/arch/x86/mm/mem_encrypt_identity.c
@@ -230,8 +230,7 @@ static void __init sme_map_range_decrypted_wp(struct sme_populate_pgd_data *ppd)
 
 static unsigned long __init sme_pgtable_calc(unsigned long len)
 {
-	unsigned long p4d_size, pud_size, pmd_size, pte_size;
-	unsigned long total;
+	unsigned long entries = 0, tables = 0;
 
 	/*
 	 * Perform a relatively simplistic calculation of the pagetable
@@ -245,42 +244,25 @@ static unsigned long __init sme_pgtable_calc(unsigned long len)
 	 * Incrementing the count for each covers the case where the addresses
 	 * cross entries.
 	 */
-	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
-		p4d_size = (ALIGN(len, PGDIR_SIZE) / PGDIR_SIZE) + 1;
-		p4d_size *= sizeof(p4d_t) * PTRS_PER_P4D;
-		pud_size = (ALIGN(len, P4D_SIZE) / P4D_SIZE) + 1;
-		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
-	} else {
-		p4d_size = 0;
-		pud_size = (ALIGN(len, PGDIR_SIZE) / PGDIR_SIZE) + 1;
-		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
-	}
-	pmd_size = (ALIGN(len, PUD_SIZE) / PUD_SIZE) + 1;
-	pmd_size *= sizeof(pmd_t) * PTRS_PER_PMD;
-	pte_size = 2 * sizeof(pte_t) * PTRS_PER_PTE;
 
-	total = p4d_size + pud_size + pmd_size + pte_size;
+	/* PGDIR_SIZE is equal to P4D_SIZE on 4-level machine. */
+	if (PTRS_PER_P4D > 1)
+		entries += (DIV_ROUND_UP(len, PGDIR_SIZE) + 1) * sizeof(p4d_t) * PTRS_PER_P4D;
+	entries += (DIV_ROUND_UP(len, P4D_SIZE) + 1) * sizeof(pud_t) * PTRS_PER_PUD;
+	entries += (DIV_ROUND_UP(len, PUD_SIZE) + 1) * sizeof(pmd_t) * PTRS_PER_PMD;
+	entries += 2 * sizeof(pte_t) * PTRS_PER_PTE;
 
 	/*
 	 * Now calculate the added pagetable structures needed to populate
 	 * the new pagetables.
 	 */
-	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
-		p4d_size = ALIGN(total, PGDIR_SIZE) / PGDIR_SIZE;
-		p4d_size *= sizeof(p4d_t) * PTRS_PER_P4D;
-		pud_size = ALIGN(total, P4D_SIZE) / P4D_SIZE;
-		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
-	} else {
-		p4d_size = 0;
-		pud_size = ALIGN(total, PGDIR_SIZE) / PGDIR_SIZE;
-		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
-	}
-	pmd_size = ALIGN(total, PUD_SIZE) / PUD_SIZE;
-	pmd_size *= sizeof(pmd_t) * PTRS_PER_PMD;
 
-	total += p4d_size + pud_size + pmd_size;
+	if (PTRS_PER_P4D > 1)
+		tables += DIV_ROUND_UP(entries, PGDIR_SIZE) * sizeof(p4d_t) * PTRS_PER_P4D;
+	tables += DIV_ROUND_UP(entries, P4D_SIZE) * sizeof(pud_t) * PTRS_PER_PUD;
+	tables += DIV_ROUND_UP(entries, PUD_SIZE) * sizeof(pmd_t) * PTRS_PER_PMD;
 
-	return total;
+	return entries + tables;
 }
 
 void __init __nostackprotector sme_encrypt_kernel(struct boot_params *bp)
-- 
2.15.1

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Re: [PATCHv3 3/3] x86/mm/encrypt: Rewrite sme_pgtable_calc()

[Tom Lendacky]

On 1/24/2018 10:36 AM, Kirill A. Shutemov wrote:
> sme_pgtable_calc() is unnecessary complex. It can be re-written in a
> more stream-lined way.
> 
> As a side effect, we would get the code ready to boot-time switching
> between paging modes.
> 
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>

Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>

> ---
>  arch/x86/mm/mem_encrypt_identity.c | 42 +++++++++++---------------------------
>  1 file changed, 12 insertions(+), 30 deletions(-)
> 
> diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c
> index 69635a02ce9e..613686cc56ae 100644
> --- a/arch/x86/mm/mem_encrypt_identity.c
> +++ b/arch/x86/mm/mem_encrypt_identity.c
> @@ -230,8 +230,7 @@ static void __init sme_map_range_decrypted_wp(struct sme_populate_pgd_data *ppd)
>  
>  static unsigned long __init sme_pgtable_calc(unsigned long len)
>  {
> -	unsigned long p4d_size, pud_size, pmd_size, pte_size;
> -	unsigned long total;
> +	unsigned long entries = 0, tables = 0;
>  
>  	/*
>  	 * Perform a relatively simplistic calculation of the pagetable
> @@ -245,42 +244,25 @@ static unsigned long __init sme_pgtable_calc(unsigned long len)
>  	 * Incrementing the count for each covers the case where the addresses
>  	 * cross entries.
>  	 */
> -	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
> -		p4d_size = (ALIGN(len, PGDIR_SIZE) / PGDIR_SIZE) + 1;
> -		p4d_size *= sizeof(p4d_t) * PTRS_PER_P4D;
> -		pud_size = (ALIGN(len, P4D_SIZE) / P4D_SIZE) + 1;
> -		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
> -	} else {
> -		p4d_size = 0;
> -		pud_size = (ALIGN(len, PGDIR_SIZE) / PGDIR_SIZE) + 1;
> -		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
> -	}
> -	pmd_size = (ALIGN(len, PUD_SIZE) / PUD_SIZE) + 1;
> -	pmd_size *= sizeof(pmd_t) * PTRS_PER_PMD;
> -	pte_size = 2 * sizeof(pte_t) * PTRS_PER_PTE;
>  
> -	total = p4d_size + pud_size + pmd_size + pte_size;
> +	/* PGDIR_SIZE is equal to P4D_SIZE on 4-level machine. */
> +	if (PTRS_PER_P4D > 1)
> +		entries += (DIV_ROUND_UP(len, PGDIR_SIZE) + 1) * sizeof(p4d_t) * PTRS_PER_P4D;
> +	entries += (DIV_ROUND_UP(len, P4D_SIZE) + 1) * sizeof(pud_t) * PTRS_PER_PUD;
> +	entries += (DIV_ROUND_UP(len, PUD_SIZE) + 1) * sizeof(pmd_t) * PTRS_PER_PMD;
> +	entries += 2 * sizeof(pte_t) * PTRS_PER_PTE;
>  
>  	/*
>  	 * Now calculate the added pagetable structures needed to populate
>  	 * the new pagetables.
>  	 */
> -	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
> -		p4d_size = ALIGN(total, PGDIR_SIZE) / PGDIR_SIZE;
> -		p4d_size *= sizeof(p4d_t) * PTRS_PER_P4D;
> -		pud_size = ALIGN(total, P4D_SIZE) / P4D_SIZE;
> -		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
> -	} else {
> -		p4d_size = 0;
> -		pud_size = ALIGN(total, PGDIR_SIZE) / PGDIR_SIZE;
> -		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
> -	}
> -	pmd_size = ALIGN(total, PUD_SIZE) / PUD_SIZE;
> -	pmd_size *= sizeof(pmd_t) * PTRS_PER_PMD;
>  
> -	total += p4d_size + pud_size + pmd_size;
> +	if (PTRS_PER_P4D > 1)
> +		tables += DIV_ROUND_UP(entries, PGDIR_SIZE) * sizeof(p4d_t) * PTRS_PER_P4D;
> +	tables += DIV_ROUND_UP(entries, P4D_SIZE) * sizeof(pud_t) * PTRS_PER_PUD;
> +	tables += DIV_ROUND_UP(entries, PUD_SIZE) * sizeof(pmd_t) * PTRS_PER_PMD;
>  
> -	return total;
> +	return entries + tables;
>  }
>  
>  void __init __nostackprotector sme_encrypt_kernel(struct boot_params *bp)
> 

Re: [PATCHv3 3/3] x86/mm/encrypt: Rewrite sme_pgtable_calc()

[Tom Lendacky]

On 1/24/2018 10:36 AM, Kirill A. Shutemov wrote:
> sme_pgtable_calc() is unnecessary complex. It can be re-written in a
> more stream-lined way.
> 
> As a side effect, we would get the code ready to boot-time switching
> between paging modes.
> 
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>

Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>

> ---
>  arch/x86/mm/mem_encrypt_identity.c | 42 +++++++++++---------------------------
>  1 file changed, 12 insertions(+), 30 deletions(-)
> 
> diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c
> index 69635a02ce9e..613686cc56ae 100644
> --- a/arch/x86/mm/mem_encrypt_identity.c
> +++ b/arch/x86/mm/mem_encrypt_identity.c
> @@ -230,8 +230,7 @@ static void __init sme_map_range_decrypted_wp(struct sme_populate_pgd_data *ppd)
>  
>  static unsigned long __init sme_pgtable_calc(unsigned long len)
>  {
> -	unsigned long p4d_size, pud_size, pmd_size, pte_size;
> -	unsigned long total;
> +	unsigned long entries = 0, tables = 0;
>  
>  	/*
>  	 * Perform a relatively simplistic calculation of the pagetable
> @@ -245,42 +244,25 @@ static unsigned long __init sme_pgtable_calc(unsigned long len)
>  	 * Incrementing the count for each covers the case where the addresses
>  	 * cross entries.
>  	 */
> -	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
> -		p4d_size = (ALIGN(len, PGDIR_SIZE) / PGDIR_SIZE) + 1;
> -		p4d_size *= sizeof(p4d_t) * PTRS_PER_P4D;
> -		pud_size = (ALIGN(len, P4D_SIZE) / P4D_SIZE) + 1;
> -		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
> -	} else {
> -		p4d_size = 0;
> -		pud_size = (ALIGN(len, PGDIR_SIZE) / PGDIR_SIZE) + 1;
> -		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
> -	}
> -	pmd_size = (ALIGN(len, PUD_SIZE) / PUD_SIZE) + 1;
> -	pmd_size *= sizeof(pmd_t) * PTRS_PER_PMD;
> -	pte_size = 2 * sizeof(pte_t) * PTRS_PER_PTE;
>  
> -	total = p4d_size + pud_size + pmd_size + pte_size;
> +	/* PGDIR_SIZE is equal to P4D_SIZE on 4-level machine. */
> +	if (PTRS_PER_P4D > 1)
> +		entries += (DIV_ROUND_UP(len, PGDIR_SIZE) + 1) * sizeof(p4d_t) * PTRS_PER_P4D;
> +	entries += (DIV_ROUND_UP(len, P4D_SIZE) + 1) * sizeof(pud_t) * PTRS_PER_PUD;
> +	entries += (DIV_ROUND_UP(len, PUD_SIZE) + 1) * sizeof(pmd_t) * PTRS_PER_PMD;
> +	entries += 2 * sizeof(pte_t) * PTRS_PER_PTE;
>  
>  	/*
>  	 * Now calculate the added pagetable structures needed to populate
>  	 * the new pagetables.
>  	 */
> -	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
> -		p4d_size = ALIGN(total, PGDIR_SIZE) / PGDIR_SIZE;
> -		p4d_size *= sizeof(p4d_t) * PTRS_PER_P4D;
> -		pud_size = ALIGN(total, P4D_SIZE) / P4D_SIZE;
> -		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
> -	} else {
> -		p4d_size = 0;
> -		pud_size = ALIGN(total, PGDIR_SIZE) / PGDIR_SIZE;
> -		pud_size *= sizeof(pud_t) * PTRS_PER_PUD;
> -	}
> -	pmd_size = ALIGN(total, PUD_SIZE) / PUD_SIZE;
> -	pmd_size *= sizeof(pmd_t) * PTRS_PER_PMD;
>  
> -	total += p4d_size + pud_size + pmd_size;
> +	if (PTRS_PER_P4D > 1)
> +		tables += DIV_ROUND_UP(entries, PGDIR_SIZE) * sizeof(p4d_t) * PTRS_PER_P4D;
> +	tables += DIV_ROUND_UP(entries, P4D_SIZE) * sizeof(pud_t) * PTRS_PER_PUD;
> +	tables += DIV_ROUND_UP(entries, PUD_SIZE) * sizeof(pmd_t) * PTRS_PER_PMD;
>  
> -	return total;
> +	return entries + tables;
>  }
>  
>  void __init __nostackprotector sme_encrypt_kernel(struct boot_params *bp)
> 

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Re: [PATCHv3 0/3] x86/mm/encrypt: Cleanup and switching between paging modes

[Tom Lendacky]

On 1/24/2018 10:36 AM, Kirill A. Shutemov wrote:
> This patcheset is a preparation set for boot-time switching between
> paging modes. Please review and consider applying.
> 
> Code around sme_populate_pgd() is unnecessary complex and hard to modify.
> 
> This patchset rewrites it in more stream-lined way to add support of
> boot-time switching between paging modes.
> 
> I haven't tested the patchset on hardware capable of memory encryption.

Tested-by: Tom Lendacky <thomas.lendacky@amd.com>

> 
> v3:
>  - Move all page table related functions into mem_encrypt_identity.c
> v2:
>  - Rebased to up-to-date tip
> 
> Kirill A. Shutemov (3):
>   x86/mm/encrypt: Move page table helpers into separate translation unit
>   x86/mm/encrypt: Rewrite sme_populate_pgd() and
>     sme_populate_pgd_large()
>   x86/mm/encrypt: Rewrite sme_pgtable_calc()
> 
>  arch/x86/mm/Makefile               |  14 +-
>  arch/x86/mm/mem_encrypt.c          | 578 +------------------------------------
>  arch/x86/mm/mem_encrypt_identity.c | 563 ++++++++++++++++++++++++++++++++++++
>  arch/x86/mm/mm_internal.h          |   1 +
>  4 files changed, 574 insertions(+), 582 deletions(-)
>  create mode 100644 arch/x86/mm/mem_encrypt_identity.c
> 

Re: [PATCHv3 0/3] x86/mm/encrypt: Cleanup and switching between paging modes

[Tom Lendacky]

On 1/24/2018 10:36 AM, Kirill A. Shutemov wrote:
> This patcheset is a preparation set for boot-time switching between
> paging modes. Please review and consider applying.
> 
> Code around sme_populate_pgd() is unnecessary complex and hard to modify.
> 
> This patchset rewrites it in more stream-lined way to add support of
> boot-time switching between paging modes.
> 
> I haven't tested the patchset on hardware capable of memory encryption.

Tested-by: Tom Lendacky <thomas.lendacky@amd.com>

> 
> v3:
>  - Move all page table related functions into mem_encrypt_identity.c
> v2:
>  - Rebased to up-to-date tip
> 
> Kirill A. Shutemov (3):
>   x86/mm/encrypt: Move page table helpers into separate translation unit
>   x86/mm/encrypt: Rewrite sme_populate_pgd() and
>     sme_populate_pgd_large()
>   x86/mm/encrypt: Rewrite sme_pgtable_calc()
> 
>  arch/x86/mm/Makefile               |  14 +-
>  arch/x86/mm/mem_encrypt.c          | 578 +------------------------------------
>  arch/x86/mm/mem_encrypt_identity.c | 563 ++++++++++++++++++++++++++++++++++++
>  arch/x86/mm/mm_internal.h          |   1 +
>  4 files changed, 574 insertions(+), 582 deletions(-)
>  create mode 100644 arch/x86/mm/mem_encrypt_identity.c
> 

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